645679976546 has 16 divisors (see below), whose sum is σ = 1056816518688. Its totient is φ = 293421652800.

The previous prime is 645679976531. The next prime is 645679976563.

645679976546 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×645679976546² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3366860 + ... + 3553463.

It is an arithmetic number, because the mean of its divisors is an integer number (66051032418).

Almost surely, 2^645679976546 is an apocalyptic number.

645679976546 is a deficient number, since it is larger than the sum of its proper divisors (411136542142).

645679976546 is a wasteful number, since it uses less digits than its factorization.

645679976546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6924577.

The product of its digits is 2057529600, while the sum is 74.

The spelling of 645679976546 in words is "six hundred forty-five billion, six hundred seventy-nine million, nine hundred seventy-six thousand, five hundred forty-six".