15964360666 has 4 divisors (see below), whose sum is σ = 23946541002. Its totient is φ = 7982180332.

The previous prime is 15964360639. The next prime is 15964360673. The reversal of 15964360666 is 66606346951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 14826715225 + 1137645441 = 121765^2 + 33729^2 .

It is a super-2 number, since 2×15964360666² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3991090165 + ... + 3991090168.

Almost surely, 2^15964360666 is an apocalyptic number.

15964360666 is a deficient number, since it is larger than the sum of its proper divisors (7982180336).

15964360666 is an equidigital number, since it uses as much as digits as its factorization.

15964360666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7982180335.

The product of its (nonzero) digits is 4199040, while the sum is 52.

The spelling of 15964360666 in words is "fifteen billion, nine hundred sixty-four million, three hundred sixty thousand, six hundred sixty-six".