391742136 has 64 divisors (see below), whose sum is σ = 1093927200. Its totient is φ = 129890304.

The previous prime is 391742077. The next prime is 391742137. The reversal of 391742136 is 631247193.

It is a super-2 number, since 2×391742136² = 306923802235684992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 391742136.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391742137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36990 + ... + 46386.

Almost surely, 2^391742136 is an apocalyptic number.

391742136 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391742136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (546963600).

391742136 is an abundant number, since it is smaller than the sum of its proper divisors (702185064).

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

391742136 is a wasteful number, since it uses less digits than its factorization.

391742136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9605 (or 9595 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 391742136 is about 19792.4767525441. The cubic root of 391742136 is about 731.7006300677.

The spelling of 391742136 in words is "three hundred ninety-one million, seven hundred forty-two thousand, one hundred thirty-six".