645897930 has 16 divisors (see below), whose sum is σ = 1550155104. Its totient is φ = 172239440.

The previous prime is 645897919. The next prime is 645897977. The reversal of 645897930 is 39798546.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10764936 + ... + 10764995.

It is an arithmetic number, because the mean of its divisors is an integer number (96884694).

Almost surely, 2^645897930 is an apocalyptic number.

645897930 is an abundant number, since it is smaller than the sum of its proper divisors (904257174).

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

645897930 is a wasteful number, since it uses less digits than its factorization.

645897930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21529941.

The product of its (nonzero) digits is 1632960, while the sum is 51.

The square root of 645897930 is about 25414.5220297373. The cubic root of 645897930 is about 864.4130157344.

The spelling of 645897930 in words is "six hundred forty-five million, eight hundred ninety-seven thousand, nine hundred thirty".