391742381 has 8 divisors (see below), whose sum is σ = 405827328. Its totient is φ = 377748000.

The previous prime is 391742369. The next prime is 391742401. The reversal of 391742381 is 183247193.

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 391742381 - 2⁶ = 391742317 is a prime.

It is a super-2 number, since 2×391742381² = 306924186143098322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391747381) 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, 13775 + ... + 31196.

It is an arithmetic number, because the mean of its divisors is an integer number (50728416).

Almost surely, 2^391742381 is an apocalyptic number.

391742381 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

391742381 is a deficient number, since it is larger than the sum of its proper divisors (14084947).

391742381 is a wasteful number, since it uses less digits than its factorization.

391742381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45283.

The product of its digits is 36288, while the sum is 38.

The square root of 391742381 is about 19792.4829417635. The cubic root of 391742381 is about 731.7007826056.

The spelling of 391742381 in words is "three hundred ninety-one million, seven hundred forty-two thousand, three hundred eighty-one".