1297890432 has 128 divisors (see below), whose sum is σ = 4056091200. Its totient is φ = 407162880.

The previous prime is 1297890431. The next prime is 1297890469. The reversal of 1297890432 is 2340987921.

1297890432 is a `hidden beast` number, since 129 + 7 + 8 + 90 + 432 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1297890431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47707 + ... + 69797.

Almost surely, 2^1297890432 is an apocalyptic number.

1297890432 is a gapful number since it is divisible by the number (12) 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 1297890432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2028045600).

1297890432 is an abundant number, since it is smaller than the sum of its proper divisors (2758200768).

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

1297890432 is a wasteful number, since it uses less digits than its factorization.

1297890432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22131 (or 22113 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1297890432 is about 36026.2464322888. The cubic root of 1297890432 is about 1090.8022128021.

The spelling of 1297890432 in words is "one billion, two hundred ninety-seven million, eight hundred ninety thousand, four hundred thirty-two".