391363664 has 20 divisors (see below), whose sum is σ = 802871604. Its totient is φ = 184171008.

The previous prime is 391363657. The next prime is 391363667. The reversal of 391363664 is 466363193.

It can be written as a sum of positive squares in 2 ways, for example, as 274896400 + 116467264 = 16580^2 + 10792^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391363667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 719147 + ... + 719690.

Almost surely, 2^391363664 is an apocalyptic number.

391363664 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

It is an amenable number.

391363664 is an abundant number, since it is smaller than the sum of its proper divisors (411507940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391363664 is a wasteful number, since it uses less digits than its factorization.

391363664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1438862 (or 1438856 counting only the distinct ones).

The product of its digits is 209952, while the sum is 41.

The square root of 391363664 is about 19782.9134355888. The cubic root of 391363664 is about 731.4649159709.

The spelling of 391363664 in words is "three hundred ninety-one million, three hundred sixty-three thousand, six hundred sixty-four".