1297520640 has 576 divisors, whose sum is σ = 5242255200. Its totient is φ = 302579712.

The previous prime is 1297520617. The next prime is 1297520647. The reversal of 1297520640 is 460257921.

1297520640 is a `hidden beast` number, since 1 + 2 + 9 + 7 + 5 + 2 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×1297520640² = 3367119622452019200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1297520595 and 1297520604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1297520647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 68290551 + ... + 68290569.

Almost surely, 2^1297520640 is an apocalyptic number.

1297520640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1297520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2621127600).

1297520640 is an abundant number, since it is smaller than the sum of its proper divisors (3944734560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1297520640 is a wasteful number, since it uses less digits than its factorization.

1297520640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 1297520640 is about 36021.1138084319. The cubic root of 1297520640 is about 1090.6986066637.

The spelling of 1297520640 in words is "one billion, two hundred ninety-seven million, five hundred twenty thousand, six hundred forty".