15640061640 has 128 divisors (see below), whose sum is σ = 55954575360. Its totient is φ = 3419437824.

The previous prime is 15640061533. The next prime is 15640061651. The reversal of 15640061640 is 4616004651.

It is a happy number.

It is a super-4 number, since 4×15640061640⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 385444 + ... + 424083.

It is an arithmetic number, because the mean of its divisors is an integer number (437145120).

Almost surely, 2^15640061640 is an apocalyptic number.

15640061640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15640061640 is an abundant number, since it is smaller than the sum of its proper divisors (40314513720).

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

15640061640 is a wasteful number, since it uses less digits than its factorization.

15640061640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809571 (or 809567 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 15640061640 in words is "fifteen billion, six hundred forty million, sixty-one thousand, six hundred forty".