645621262600 has 48 divisors (see below), whose sum is σ = 1501124764500. Its totient is φ = 258238986240.

The previous prime is 645621262591. The next prime is 645621262619. The reversal of 645621262600 is 6262126546.

It can be written as a sum of positive squares in 6 ways, for example, as 515526872004 + 130094390596 = 718002^2 + 360686^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8331232 + ... + 8408368.

Almost surely, 2^645621262600 is an apocalyptic number.

It is an amenable number.

645621262600 is an abundant number, since it is smaller than the sum of its proper divisors (855503501900).

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

645621262600 is a wasteful number, since it uses less digits than its factorization.

645621262600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119002 (or 118993 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 645621262600 in words is "six hundred forty-five billion, six hundred twenty-one million, two hundred sixty-two thousand, six hundred".