640616945 has 8 divisors (see below), whose sum is σ = 774271680. Its totient is φ = 508806000.

The previous prime is 640616903. The next prime is 640616959. The reversal of 640616945 is 549616046.

640616945 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640616945 - 2⁸ = 640616689 is a prime.

It is a super-2 number, since 2×640616945² = 820780140442266050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 460181 + ... + 461570.

It is an arithmetic number, because the mean of its divisors is an integer number (96783960).

Almost surely, 2^640616945 is an apocalyptic number.

It is an amenable number.

640616945 is a deficient number, since it is larger than the sum of its proper divisors (133654735).

640616945 is a wasteful number, since it uses less digits than its factorization.

640616945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921895.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 640616945 is about 25310.4117904075. The cubic root of 640616945 is about 862.0506970217.

The spelling of 640616945 in words is "six hundred forty million, six hundred sixteen thousand, nine hundred forty-five".