815397940188 has 216 divisors, whose sum is σ = 2364218019072. Its totient is φ = 235451563776.

The previous prime is 815397940177. The next prime is 815397940193. The reversal of 815397940188 is 881049793518.

815397940188 is a `hidden beast` number, since 8 + 1 + 539 + 7 + 94 + 0 + 1 + 8 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 13090245 + ... + 13152387.

It is an arithmetic number, because the mean of its divisors is an integer number (10945453792).

Almost surely, 2^815397940188 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815397940188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1182109009536).

815397940188 is an abundant number, since it is smaller than the sum of its proper divisors (1548820078884).

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

815397940188 is a wasteful number, since it uses less digits than its factorization.

815397940188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62265 (or 62237 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 63.

The spelling of 815397940188 in words is "eight hundred fifteen billion, three hundred ninety-seven million, nine hundred forty thousand, one hundred eighty-eight".