644051213 has 8 divisors (see below), whose sum is σ = 702374400. Its totient is φ = 586982448.

The previous prime is 644051207. The next prime is 644051249. The reversal of 644051213 is 312150446.

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

It is not a de Polignac number, because 644051213 - 2¹⁰ = 644050189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644051203) 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, 312533 + ... + 314586.

It is an arithmetic number, because the mean of its divisors is an integer number (87796800).

Almost surely, 2^644051213 is an apocalyptic number.

It is an amenable number.

644051213 is a deficient number, since it is larger than the sum of its proper divisors (58323187).

644051213 is a wasteful number, since it uses less digits than its factorization.

644051213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 627211.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 644051213 is about 25378.1640982952. The cubic root of 644051213 is about 863.5884014338.

The spelling of 644051213 in words is "six hundred forty-four million, fifty-one thousand, two hundred thirteen".