391242155 has 8 divisors (see below), whose sum is σ = 469643184. Its totient is φ = 312892000.

The previous prime is 391242139. The next prime is 391242193. The reversal of 391242155 is 551242193.

391242155 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 391242155 - 2⁴ = 391242139 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6980 + ... + 28830.

It is an arithmetic number, because the mean of its divisors is an integer number (58705398).

Almost surely, 2^391242155 is an apocalyptic number.

391242155 is a deficient number, since it is larger than the sum of its proper divisors (78401029).

391242155 is a wasteful number, since it uses less digits than its factorization.

391242155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25437.

The product of its digits is 10800, while the sum is 32.

The square root of 391242155 is about 19779.8421378938. The cubic root of 391242155 is about 731.3892073836.

The spelling of 391242155 in words is "three hundred ninety-one million, two hundred forty-two thousand, one hundred fifty-five".