645264402500 has 60 divisors (see below), whose sum is σ = 1411619309100. Its totient is φ = 258004224000.

The previous prime is 645264402463. The next prime is 645264402521. The reversal of 645264402500 is 5204462546.

It can be written as a sum of positive squares in 10 ways, for example, as 593565466624 + 51698935876 = 770432^2 + 227374^2 .

It is a super-2 number, since 2×645264402500² (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 19 ways as a sum of consecutive naturals, for example, 6473036 + ... + 6571964.

It is an arithmetic number, because the mean of its divisors is an integer number (23526988485).

Almost surely, 2^645264402500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645264402500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (705809654550).

645264402500 is an abundant number, since it is smaller than the sum of its proper divisors (766354906600).

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

645264402500 is a wasteful number, since it uses less digits than its factorization.

645264402500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101562 (or 101545 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 38.

The spelling of 645264402500 in words is "six hundred forty-five billion, two hundred sixty-four million, four hundred two thousand, five hundred".