645532370 has 24 divisors (see below), whose sum is σ = 1351666764. Its totient is φ = 221325216.

The previous prime is 645532369. The next prime is 645532411. The reversal of 645532370 is 73235546.

It can be written as a sum of positive squares in 2 ways, for example, as 645312409 + 219961 = 25403^2 + 469^2 .

It is a super-3 number, since 3×645532370³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 645532370.

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, 658217 + ... + 659196.

Almost surely, 2^645532370 is an apocalyptic number.

645532370 is an abundant number, since it is smaller than the sum of its proper divisors (706134394).

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

645532370 is a wasteful number, since it uses less digits than its factorization.

645532370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1317434 (or 1317427 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 35.

The square root of 645532370 is about 25407.3290607258. The cubic root of 645532370 is about 864.2499071684.

The spelling of 645532370 in words is "six hundred forty-five million, five hundred thirty-two thousand, three hundred seventy".