391140428 has 24 divisors (see below), whose sum is σ = 783633312. Its totient is φ = 167341824.

The previous prime is 391140419. The next prime is 391140433. The reversal of 391140428 is 824041193.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 391140394 and 391140403.

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, 4826 + ... + 28382.

It is an arithmetic number, because the mean of its divisors is an integer number (32651388).

Almost surely, 2^391140428 is an apocalyptic number.

It is an amenable number.

391140428 is an abundant number, since it is smaller than the sum of its proper divisors (392492884).

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

391140428 is a wasteful number, since it uses less digits than its factorization.

391140428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24161 (or 24159 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 391140428 is about 19777.2704891246. The cubic root of 391140428 is about 731.3258123069.

The spelling of 391140428 in words is "three hundred ninety-one million, one hundred forty thousand, four hundred twenty-eight".