16515565440 has 128 divisors (see below), whose sum is σ = 57429198720. Its totient is φ = 4003768320.

The previous prime is 16515565411. The next prime is 16515565447. The reversal of 16515565440 is 4456551561.

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

It is a junction number, because it is equal to n+sod(n) for n = 16515565392 and 16515565401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16515565447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369874 + ... + 412113.

It is an arithmetic number, because the mean of its divisors is an integer number (448665615).

Almost surely, 2^16515565440 is an apocalyptic number.

16515565440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16515565440 is an abundant number, since it is smaller than the sum of its proper divisors (40913633280).

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

16515565440 is a wasteful number, since it uses less digits than its factorization.

16515565440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782020 (or 782008 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 42.

The spelling of 16515565440 in words is "sixteen billion, five hundred fifteen million, five hundred sixty-five thousand, four hundred forty".