15640434320 has 80 divisors (see below), whose sum is σ = 41664142848. Its totient is φ = 5348851200.

The previous prime is 15640434319. The next prime is 15640434361. The reversal of 15640434320 is 2343404651.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 187145 + ... + 257495.

Almost surely, 2^15640434320 is an apocalyptic number.

15640434320 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 15640434320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20832071424).

15640434320 is an abundant number, since it is smaller than the sum of its proper divisors (26023708528).

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

15640434320 is a wasteful number, since it uses less digits than its factorization.

15640434320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70768 (or 70762 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 32.

Adding to 15640434320 its reverse (2343404651), we get a palindrome (17983838971).

The spelling of 15640434320 in words is "fifteen billion, six hundred forty million, four hundred thirty-four thousand, three hundred twenty".