645545944064 has 44 divisors (see below), whose sum is σ = 1474813127424. Its totient is φ = 276662544384.

The previous prime is 645545944063. The next prime is 645545944067. The reversal of 645545944064 is 460449545546.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is not an unprimeable number, because it can be changed into a prime (645545944063) 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, 45022544 + ... + 45036879.

Almost surely, 2^645545944064 is an apocalyptic number.

645545944064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

645545944064 is an abundant number, since it is smaller than the sum of its proper divisors (829267183360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645545944064 is an equidigital number, since it uses as much as digits as its factorization.

645545944064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90059450 (or 90059432 counting only the distinct ones).

The product of its (nonzero) digits is 41472000, while the sum is 56.

The spelling of 645545944064 in words is "six hundred forty-five billion, five hundred forty-five million, nine hundred forty-four thousand, sixty-four".