645254464 has 28 divisors (see below), whose sum is σ = 1281315700. Its totient is φ = 322403328.

The previous prime is 645254447. The next prime is 645254473. The reversal of 645254464 is 464452546.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 441336064 + 203918400 = 21008^2 + 14280^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127372 + ... + 132340.

It is an arithmetic number, because the mean of its divisors is an integer number (45761275).

Almost surely, 2^645254464 is an apocalyptic number.

645254464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

645254464 is a deficient number, since it is larger than the sum of its proper divisors (636061236).

645254464 is a wasteful number, since it uses less digits than its factorization.

645254464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7010 (or 7000 counting only the distinct ones).

The product of its digits is 460800, while the sum is 40.

The square root of 645254464 is about 25401.8594594963. The cubic root of 645254464 is about 864.1258675795.

The spelling of 645254464 in words is "six hundred forty-five million, two hundred fifty-four thousand, four hundred sixty-four".