15766820356 has 27 divisors (see below), whose sum is σ = 32100320469. Its totient is φ = 6756455328.

The previous prime is 15766820341. The next prime is 15766820387. The reversal of 15766820356 is 65302866751.

The square root of 15766820356 is 125566.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 8329482756 + 7437337600 = 91266^2 + 86240^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1753440 + ... + 1762408.

Almost surely, 2^15766820356 is an apocalyptic number.

15766820356 is the 125566-th square number.

It is an amenable number.

15766820356 is an abundant number, since it is smaller than the sum of its proper divisors (16333500113).

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

15766820356 is an frugal number, since it uses more digits than its factorization.

15766820356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17956 (or 8978 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 49.

Multiplying 15766820356 by its sum of digits (49), we get a square (772574197444 = 878962²).

15766820356 divided by its sum of digits (49) gives a square (321771844 = 17938²).

The spelling of 15766820356 in words is "fifteen billion, seven hundred sixty-six million, eight hundred twenty thousand, three hundred fifty-six".