645556052 has 24 divisors (see below), whose sum is σ = 1150269120. Its totient is φ = 316921280.

The previous prime is 645556039. The next prime is 645556061. The reversal of 645556052 is 250655546.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 645555997 and 645556015.

It is a congruent number.

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, 348593 + ... + 350439.

It is an arithmetic number, because the mean of its divisors is an integer number (47927880).

Almost surely, 2^645556052 is an apocalyptic number.

It is an amenable number.

645556052 is a deficient number, since it is larger than the sum of its proper divisors (504713068).

645556052 is a wasteful number, since it uses less digits than its factorization.

645556052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3391 (or 3389 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 38.

The square root of 645556052 is about 25407.7951030781. The cubic root of 645556052 is about 864.2604756629.

It can be divided in two parts, 64555 and 6052, that added together give a palindrome (70607).

The spelling of 645556052 in words is "six hundred forty-five million, five hundred fifty-six thousand, fifty-two".