15942537640 has 16 divisors (see below), whose sum is σ = 35870709780. Its totient is φ = 6377015040.

The previous prime is 15942537587. The next prime is 15942537643. The reversal of 15942537640 is 4673524951.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15600509604 + 342028036 = 124902^2 + 18494^2 .

It is not an unprimeable number, because it can be changed into a prime (15942537643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199281681 + ... + 199281760.

Almost surely, 2^15942537640 is an apocalyptic number.

15942537640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15942537640 is an abundant number, since it is smaller than the sum of its proper divisors (19928172140).

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

15942537640 is a wasteful number, since it uses less digits than its factorization.

15942537640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398563452 (or 398563448 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 46.

The spelling of 15942537640 in words is "fifteen billion, nine hundred forty-two million, five hundred thirty-seven thousand, six hundred forty".