391092121 has 4 divisors (see below), whose sum is σ = 446962432. Its totient is φ = 335221812.

The previous prime is 391092101. The next prime is 391092127. The reversal of 391092121 is 121290193.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 391092121 - 2¹⁷ = 390961049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 391092121.

It is not an unprimeable number, because it can be changed into a prime (391092127) 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, 27935145 + ... + 27935158.

It is an arithmetic number, because the mean of its divisors is an integer number (111740608).

Almost surely, 2^391092121 is an apocalyptic number.

It is an amenable number.

391092121 is a deficient number, since it is larger than the sum of its proper divisors (55870311).

391092121 is an equidigital number, since it uses as much as digits as its factorization.

391092121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55870310.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 391092121 is about 19776.0491757075. The cubic root of 391092121 is about 731.2957041003.

The spelling of 391092121 in words is "three hundred ninety-one million, ninety-two thousand, one hundred twenty-one".