391638342 has 64 divisors (see below), whose sum is σ = 841052160. Its totient is φ = 121301664.

The previous prime is 391638341. The next prime is 391638349. The reversal of 391638342 is 243836193.

It is a self number, because there is not a number n which added to its sum of digits gives 391638342.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391638341) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 838393 + ... + 838859.

It is an arithmetic number, because the mean of its divisors is an integer number (13141440).

Almost surely, 2^391638342 is an apocalyptic number.

391638342 is an abundant number, since it is smaller than the sum of its proper divisors (449413818).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391638342 is a wasteful number, since it uses less digits than its factorization.

391638342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657.

The product of its digits is 93312, while the sum is 39.

The square root of 391638342 is about 19789.8545219514. The cubic root of 391638342 is about 731.6360018028.

The spelling of 391638342 in words is "three hundred ninety-one million, six hundred thirty-eight thousand, three hundred forty-two".