15664081563 has 48 divisors (see below), whose sum is σ = 25313156960. Its totient is φ = 9622520064.

The previous prime is 15664081561. The next prime is 15664081579. The reversal of 15664081563 is 36518046651.

15664081563 is a `hidden beast` number, since 1 + 5 + 6 + 6 + 4 + 0 + 81 + 563 = 666.

It is not a de Polignac number, because 15664081563 - 2¹ = 15664081561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15664081561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1932423 + ... + 1940511.

Almost surely, 2^15664081563 is an apocalyptic number.

15664081563 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

15664081563 is a deficient number, since it is larger than the sum of its proper divisors (9649075397).

15664081563 is an equidigital number, since it uses as much as digits as its factorization.

15664081563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8730 (or 8718 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 15664081563 in words is "fifteen billion, six hundred sixty-four million, eighty-one thousand, five hundred sixty-three".