391339624987 has 4 divisors (see below), whose sum is σ = 391345632216. Its totient is φ = 391333617760.

The previous prime is 391339624979. The next prime is 391339624993. The reversal of 391339624987 is 789426933193.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 391339624987 - 2³ = 391339624979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391339624937) 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, 2904814 + ... + 3036547.

It is an arithmetic number, because the mean of its divisors is an integer number (97836408054).

Almost surely, 2^391339624987 is an apocalyptic number.

391339624987 is a deficient number, since it is larger than the sum of its proper divisors (6007229).

391339624987 is an equidigital number, since it uses as much as digits as its factorization.

391339624987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6007228.

The product of its digits is 52907904, while the sum is 64.

The spelling of 391339624987 in words is "three hundred ninety-one billion, three hundred thirty-nine million, six hundred twenty-four thousand, nine hundred eighty-seven".