645637676 has 12 divisors (see below), whose sum is σ = 1130051160. Its totient is φ = 322765920.

The previous prime is 645637673. The next prime is 645637687. The reversal of 645637676 is 676736546.

It is not an unprimeable number, because it can be changed into a prime (645637673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29696 + ... + 46616.

It is an arithmetic number, because the mean of its divisors is an integer number (94170930).

Almost surely, 2^645637676 is an apocalyptic number.

It is an amenable number.

645637676 is a deficient number, since it is larger than the sum of its proper divisors (484413484).

645637676 is a wasteful number, since it uses less digits than its factorization.

645637676 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26464 (or 26462 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 50.

The square root of 645637676 is about 25409.4013310035. The cubic root of 645637676 is about 864.2968997782.

The spelling of 645637676 in words is "six hundred forty-five million, six hundred thirty-seven thousand, six hundred seventy-six".