391641644 has 6 divisors (see below), whose sum is σ = 685372884. Its totient is φ = 195820820.

The previous prime is 391641643. The next prime is 391641659. The reversal of 391641644 is 446146193.

It is a junction number, because it is equal to n+sod(n) for n = 391641598 and 391641607.

It is not an unprimeable number, because it can be changed into a prime (391641641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48955202 + ... + 48955209.

It is an arithmetic number, because the mean of its divisors is an integer number (114228814).

Almost surely, 2^391641644 is an apocalyptic number.

It is an amenable number.

391641644 is a deficient number, since it is larger than the sum of its proper divisors (293731240).

391641644 is a wasteful number, since it uses less digits than its factorization.

391641644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97910415 (or 97910413 counting only the distinct ones).

The product of its digits is 62208, while the sum is 38.

The square root of 391641644 is about 19789.9379483615. The cubic root of 391641644 is about 731.6380579985.

The spelling of 391641644 in words is "three hundred ninety-one million, six hundred forty-one thousand, six hundred forty-four".