645927264 has 96 divisors (see below), whose sum is σ = 1896814080. Its totient is φ = 213840000.

The previous prime is 645927263. The next prime is 645927277. The reversal of 645927264 is 462729546.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645927263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127989 + ... + 132939.

It is an arithmetic number, because the mean of its divisors is an integer number (19758480).

Almost surely, 2^645927264 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 645927264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (948407040).

645927264 is an abundant number, since it is smaller than the sum of its proper divisors (1250886816).

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

645927264 is a wasteful number, since it uses less digits than its factorization.

645927264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5121 (or 5107 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 645927264 is about 25415.0991341761. The cubic root of 645927264 is about 864.4261015520.

The spelling of 645927264 in words is "six hundred forty-five million, nine hundred twenty-seven thousand, two hundred sixty-four".