391290055 has 16 divisors (see below), whose sum is σ = 507054240. Its totient is φ = 288160128.

The previous prime is 391290023. The next prime is 391290079. The reversal of 391290055 is 550092193.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 391290055 - 2⁵ = 391290023 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 391290055.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16176 + ... + 32314.

It is an arithmetic number, because the mean of its divisors is an integer number (31690890).

Almost surely, 2^391290055 is an apocalyptic number.

391290055 is a deficient number, since it is larger than the sum of its proper divisors (115764185).

391290055 is a wasteful number, since it uses less digits than its factorization.

391290055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16530.

The product of its (nonzero) digits is 12150, while the sum is 34.

The square root of 391290055 is about 19781.0529295081. The cubic root of 391290055 is about 731.4190542981.

The spelling of 391290055 in words is "three hundred ninety-one million, two hundred ninety thousand, fifty-five".