391872040 has 32 divisors (see below), whose sum is σ = 1007671680. Its totient is φ = 134356032.

The previous prime is 391872011. The next prime is 391872043. The reversal of 391872040 is 40278193.

It is a junction number, because it is equal to n+sod(n) for n = 391871987 and 391872005.

It is not an unprimeable number, because it can be changed into a prime (391872043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 699492 + ... + 700051.

It is an arithmetic number, because the mean of its divisors is an integer number (31489740).

Almost surely, 2^391872040 is an apocalyptic number.

It is an amenable number.

391872040 is an abundant number, since it is smaller than the sum of its proper divisors (615799640).

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

391872040 is a wasteful number, since it uses less digits than its factorization.

391872040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399561 (or 1399557 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 391872040 is about 19795.7581314786. The cubic root of 391872040 is about 731.7814998758.

The spelling of 391872040 in words is "three hundred ninety-one million, eight hundred seventy-two thousand, forty".