645969492 has 60 divisors (see below), whose sum is σ = 1929940320. Its totient is φ = 184562064.

The previous prime is 645969487. The next prime is 645969497. The reversal of 645969492 is 294969546.

It is a happy number.

645969492 is a `hidden beast` number, since 6 + 4 + 596 + 9 + 49 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (645969487) and next prime (645969497).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645969497) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 140142 + ... + 144677.

It is an arithmetic number, because the mean of its divisors is an integer number (32165672).

Almost surely, 2^645969492 is an apocalyptic number.

It is an amenable number.

645969492 is an abundant number, since it is smaller than the sum of its proper divisors (1283970828).

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

645969492 is a wasteful number, since it uses less digits than its factorization.

645969492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284842 (or 284831 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 54.

The square root of 645969492 is about 25415.9298865888. The cubic root of 645969492 is about 864.4449386523. Note that the first 3 decimals are identical.

Adding to 645969492 its sum of digits (54), we get a palindrome (645969546).

It can be divided in two parts, 64596 and 9492, that added together give a cube (74088 = 42³).

The spelling of 645969492 in words is "six hundred forty-five million, nine hundred sixty-nine thousand, four hundred ninety-two".