391931242 has 8 divisors (see below), whose sum is σ = 589474116. Its totient is φ = 195439872.

The previous prime is 391931231. The next prime is 391931257. The reversal of 391931242 is 242139193.

It can be written as a sum of positive squares in 2 ways, for example, as 356039161 + 35892081 = 18869^2 + 5991^2 .

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

It is a super-2 number, since 2×391931242² = 307220196911325128, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 391931198 and 391931207.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 261943 + ... + 263434.

Almost surely, 2^391931242 is an apocalyptic number.

391931242 is a deficient number, since it is larger than the sum of its proper divisors (197542874).

391931242 is a wasteful number, since it uses less digits than its factorization.

391931242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525752.

The product of its digits is 11664, while the sum is 34.

The square root of 391931242 is about 19797.2533953576. The cubic root of 391931242 is about 731.8183492743.

The spelling of 391931242 in words is "three hundred ninety-one million, nine hundred thirty-one thousand, two hundred forty-two".