391407891876 has 45 divisors (see below), whose sum is σ = 1023246984529. Its totient is φ = 130465543536.

The previous prime is 391407891841. The next prime is 391407891877. The reversal of 391407891876 is 678198704193.

The square root of 391407891876 is 625626.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 94574700900 + 296833190976 = 307530^2 + 544824^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391407891877) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 11243890 + ... + 11278646.

Almost surely, 2^391407891876 is an apocalyptic number.

391407891876 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

391407891876 is the 625626-th square number.

It is an amenable number.

391407891876 is an abundant number, since it is smaller than the sum of its proper divisors (631839092653).

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

391407891876 is an frugal number, since it uses more digits than its factorization.

391407891876 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69530 (or 34762 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 63.

The spelling of 391407891876 in words is "three hundred ninety-one billion, four hundred seven million, eight hundred ninety-one thousand, eight hundred seventy-six".