391138963 has 8 divisors (see below), whose sum is σ = 395413200. Its totient is φ = 386872800.

The previous prime is 391138939. The next prime is 391138981. The reversal of 391138963 is 369831193.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 391138963 - 2⁵ = 391138931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391139963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195856 + ... + 197842.

It is an arithmetic number, because the mean of its divisors is an integer number (49426650).

Almost surely, 2^391138963 is an apocalyptic number.

391138963 is a deficient number, since it is larger than the sum of its proper divisors (4274237).

391138963 is a wasteful number, since it uses less digits than its factorization.

391138963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4037.

The product of its digits is 104976, while the sum is 43.

The square root of 391138963 is about 19777.2334516231. The cubic root of 391138963 is about 731.3248992558.

The spelling of 391138963 in words is "three hundred ninety-one million, one hundred thirty-eight thousand, nine hundred sixty-three".