391872813969 has 32 divisors (see below), whose sum is σ = 644303156224. Its totient is φ = 206306844480.

The previous prime is 391872813967. The next prime is 391872813977. The reversal of 391872813969 is 969318278193.

It is not a de Polignac number, because 391872813969 - 2¹ = 391872813967 is a prime.

It is a super-2 number, since 2×391872813969² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (391872813967) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1229527 + ... + 1515084.

It is an arithmetic number, because the mean of its divisors is an integer number (20134473632).

Almost surely, 2^391872813969 is an apocalyptic number.

391872813969 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

It is an amenable number.

391872813969 is a deficient number, since it is larger than the sum of its proper divisors (252430342255).

391872813969 is a wasteful number, since it uses less digits than its factorization.

391872813969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2745157.

The product of its digits is 35271936, while the sum is 66.

The spelling of 391872813969 in words is "three hundred ninety-one billion, eight hundred seventy-two million, eight hundred thirteen thousand, nine hundred sixty-nine".