1664855972516 has 24 divisors (see below), whose sum is σ = 3178775305440. Its totient is φ = 756654166400.

The previous prime is 1664855972513. The next prime is 1664855972561. The reversal of 1664855972516 is 6152795584661.

It is a super-2 number, since 2×1664855972516² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1664855972513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2121461 + ... + 2798268.

It is an arithmetic number, because the mean of its divisors is an integer number (132448971060).

Almost surely, 2^{1664855972516} is an apocalyptic number.

It is an amenable number.

1664855972516 is a deficient number, since it is larger than the sum of its proper divisors (1513919332924).

1664855972516 is a wasteful number, since it uses less digits than its factorization.

1664855972516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4927435 (or 4927433 counting only the distinct ones).

The product of its digits is 108864000, while the sum is 65.

The spelling of 1664855972516 in words is "one trillion, six hundred sixty-four billion, eight hundred fifty-five million, nine hundred seventy-two thousand, five hundred sixteen".