644662347 has 16 divisors (see below), whose sum is σ = 983365632. Its totient is φ = 367994880.

The previous prime is 644662313. The next prime is 644662349. The reversal of 644662347 is 743266446.

It is not a de Polignac number, because 644662347 - 2⁶ = 644662283 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644662299 and 644662308.

It is not an unprimeable number, because it can be changed into a prime (644662349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5323 + ... + 36299.

It is an arithmetic number, because the mean of its divisors is an integer number (61460352).

Almost surely, 2^644662347 is an apocalyptic number.

644662347 is a deficient number, since it is larger than the sum of its proper divisors (338703285).

644662347 is a wasteful number, since it uses less digits than its factorization.

644662347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31978.

The product of its digits is 580608, while the sum is 42.

The square root of 644662347 is about 25390.2017912422. The cubic root of 644662347 is about 863.8614653248.

The spelling of 644662347 in words is "six hundred forty-four million, six hundred sixty-two thousand, three hundred forty-seven".