15640432251 has 8 divisors (see below), whose sum is σ = 20919696144. Its totient is φ = 10394061600.

The previous prime is 15640432231. The next prime is 15640432253. The reversal of 15640432251 is 15223404651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15640432251 - 2⁶ = 15640432187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15640432253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8222200 + ... + 8224101.

It is an arithmetic number, because the mean of its divisors is an integer number (2614962018).

Almost surely, 2^15640432251 is an apocalyptic number.

15640432251 is a deficient number, since it is larger than the sum of its proper divisors (5279263893).

15640432251 is a wasteful number, since it uses less digits than its factorization.

15640432251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16446621.

The product of its (nonzero) digits is 28800, while the sum is 33.

The spelling of 15640432251 in words is "fifteen billion, six hundred forty million, four hundred thirty-two thousand, two hundred fifty-one".