615991398 has 24 divisors (see below), whose sum is σ = 1354164504. Its totient is φ = 186663840.

The previous prime is 615991289. The next prime is 615991417. The reversal of 615991398 is 893199516.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 615991398.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 423511 + ... + 424962.

It is an arithmetic number, because the mean of its divisors is an integer number (56423521).

Almost surely, 2^615991398 is an apocalyptic number.

615991398 is an abundant number, since it is smaller than the sum of its proper divisors (738173106).

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

615991398 is a wasteful number, since it uses less digits than its factorization.

615991398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848500 (or 848489 counting only the distinct ones).

The product of its digits is 524880, while the sum is 51.

The square root of 615991398 is about 24819.1739991483. The cubic root of 615991398 is about 850.8602124344.

The spelling of 615991398 in words is "six hundred fifteen million, nine hundred ninety-one thousand, three hundred ninety-eight".