645503076 has 72 divisors (see below), whose sum is σ = 1674376704. Its totient is φ = 209583360.

The previous prime is 645503063. The next prime is 645503081. The reversal of 645503076 is 670305546.

645503076 is a `hidden beast` number, since 6 + 4 + 550 + 30 + 76 = 666.

It is a super-2 number, since 2×645503076² = 833348442250923552, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 645503076.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 406981 + ... + 408563.

It is an arithmetic number, because the mean of its divisors is an integer number (23255232).

Almost surely, 2^645503076 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 645503076, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (837188352).

645503076 is an abundant number, since it is smaller than the sum of its proper divisors (1028873628).

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

645503076 is a wasteful number, since it uses less digits than its factorization.

645503076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1881 (or 1876 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 36.

The square root of 645503076 is about 25406.7525669850. The cubic root of 645503076 is about 864.2368338659.

The spelling of 645503076 in words is "six hundred forty-five million, five hundred three thousand, seventy-six".