645453630 has 64 divisors (see below), whose sum is σ = 1738324800. Its totient is φ = 170409600.

The previous prime is 645453629. The next prime is 645453631. The reversal of 645453630 is 36354546.

645453630 is a `hidden beast` number, since 645 + 4 + 5 + 3 + 6 + 3 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (645453629) and next prime (645453631).

It is a super-2 number, since 2×645453630² = 833220776960353800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645453631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15436 + ... + 39104.

It is an arithmetic number, because the mean of its divisors is an integer number (27161325).

Almost surely, 2^645453630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645453630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (869162400).

645453630 is an abundant number, since it is smaller than the sum of its proper divisors (1092871170).

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

645453630 is a wasteful number, since it uses less digits than its factorization.

645453630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23786 (or 23780 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The square root of 645453630 is about 25405.7794605873. The cubic root of 645453630 is about 864.2147662480.

The spelling of 645453630 in words is "six hundred forty-five million, four hundred fifty-three thousand, six hundred thirty".