391479988 has 12 divisors (see below), whose sum is σ = 685768132. Its totient is φ = 195546240.

The previous prime is 391479983. The next prime is 391480021. The reversal of 391479988 is 889974193.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 118635664 + 272844324 = 10892^2 + 16518^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391479983) 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, 43845 + ... + 52012.

Almost surely, 2^391479988 is an apocalyptic number.

It is an amenable number.

391479988 is a deficient number, since it is larger than the sum of its proper divisors (294288144).

391479988 is a wasteful number, since it uses less digits than its factorization.

391479988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96882 (or 96880 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 58.

The square root of 391479988 is about 19785.8532290119. The cubic root of 391479988 is about 731.5373792611.

The spelling of 391479988 in words is "three hundred ninety-one million, four hundred seventy-nine thousand, nine hundred eighty-eight".