645213957 has 8 divisors (see below), whose sum is σ = 868803360. Its totient is φ = 425883600.

The previous prime is 645213929. The next prime is 645213977. The reversal of 645213957 is 759312546.

645213957 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 645213957 - 2⁶ = 645213893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645213977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1064407 + ... + 1065012.

It is an arithmetic number, because the mean of its divisors is an integer number (108600420).

Almost surely, 2^645213957 is an apocalyptic number.

It is an amenable number.

645213957 is a deficient number, since it is larger than the sum of its proper divisors (223589403).

645213957 is a wasteful number, since it uses less digits than its factorization.

645213957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2129523.

The product of its digits is 226800, while the sum is 42.

The square root of 645213957 is about 25401.0621234625. The cubic root of 645213957 is about 864.1077848535.

The spelling of 645213957 in words is "six hundred forty-five million, two hundred thirteen thousand, nine hundred fifty-seven".