15665566620 has 96 divisors (see below), whose sum is σ = 48325165056. Its totient is φ = 3760096000.

The previous prime is 15665566613. The next prime is 15665566643. The reversal of 15665566620 is 2666556651.

It is a self number, because there is not a number n which added to its sum of digits gives 15665566620.

It is a congruent number.

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, 50844 + ... + 184163.

It is an arithmetic number, because the mean of its divisors is an integer number (503387136).

Almost surely, 2^15665566620 is an apocalyptic number.

15665566620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15665566620 is an abundant number, since it is smaller than the sum of its proper divisors (32659598436).

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

15665566620 is a wasteful number, since it uses less digits than its factorization.

15665566620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235131 (or 235129 counting only the distinct ones).

The product of its (nonzero) digits is 1944000, while the sum is 48.

It can be divided in two parts, 15665 and 566620, that added together give a palindrome (582285).

The spelling of 15665566620 in words is "fifteen billion, six hundred sixty-five million, five hundred sixty-six thousand, six hundred twenty".