815961078720 has 672 divisors, whose sum is σ = 3093699907584. Its totient is φ = 196709990400.

The previous prime is 815961078707. The next prime is 815961078731. The reversal of 815961078720 is 27870169518.

815961078720 is a `hidden beast` number, since 8 + 15 + 9 + 610 + 7 + 8 + 7 + 2 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 88293300 + ... + 88302540.

Almost surely, 2^815961078720 is an apocalyptic number.

815961078720 is a gapful number since it is divisible by the number (80) 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 815961078720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1546849953792).

815961078720 is an abundant number, since it is smaller than the sum of its proper divisors (2277738828864).

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

815961078720 is a wasteful number, since it uses less digits than its factorization.

815961078720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9361 (or 9348 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 54.

The spelling of 815961078720 in words is "eight hundred fifteen billion, nine hundred sixty-one million, seventy-eight thousand, seven hundred twenty".