1297347840 has 432 divisors, whose sum is σ = 4812295488. Its totient is φ = 334430208.

The previous prime is 1297347839. The next prime is 1297347841. The reversal of 1297347840 is 487437921.

It is an interprime number because it is at equal distance from previous prime (1297347839) and next prime (1297347841).

It is a tau number, because it is divible by the number of its divisors (432).

It is a super-2 number, since 2×1297347840² = 3366222835905331200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1297347841) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13374672 + ... + 13374768.

Almost surely, 2^1297347840 is an apocalyptic number.

1297347840 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 1297347840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2406147744).

1297347840 is an abundant number, since it is smaller than the sum of its proper divisors (3514947648).

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

1297347840 is an frugal number, since it uses more digits than its factorization.

1297347840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 1297347840 is about 36018.7151353293. The cubic root of 1297347840 is about 1090.6501858317.

The spelling of 1297347840 in words is "one billion, two hundred ninety-seven million, three hundred forty-seven thousand, eight hundred forty".