15665605506 has 24 divisors (see below), whose sum is σ = 34091679024. Its totient is φ = 5198863320.

The previous prime is 15665605447. The next prime is 15665605511. The reversal of 15665605506 is 60550656651.

It is a super-2 number, since 2×15665605506² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1912900 + ... + 1921071.

It is an arithmetic number, because the mean of its divisors is an integer number (1420486626).

Almost surely, 2^15665605506 is an apocalyptic number.

15665605506 is an abundant number, since it is smaller than the sum of its proper divisors (18426073518).

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

15665605506 is a wasteful number, since it uses less digits than its factorization.

15665605506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3834206 (or 3834203 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The spelling of 15665605506 in words is "fifteen billion, six hundred sixty-five million, six hundred five thousand, five hundred six".