20815699773960 has 512 divisors, whose sum is σ = 90421146547200. Its totient is φ = 4133537464320.

The previous prime is 20815699773899. The next prime is 20815699773971. The reversal of 20815699773960 is 6937799651802.

20815699773960 is a `hidden beast` number, since 2 + 0 + 81 + 5 + 6 + 99 + 77 + 396 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4558651 + ... + 7900170.

It is an arithmetic number, because the mean of its divisors is an integer number (176603801850).

Almost surely, 2^{20815699773960} is an apocalyptic number.

20815699773960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20815699773960 is an abundant number, since it is smaller than the sum of its proper divisors (69605446773240).

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

20815699773960 is a wasteful number, since it uses less digits than its factorization.

20815699773960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12458878 (or 12458868 counting only the distinct ones).

The product of its (nonzero) digits is 308629440, while the sum is 72.

The spelling of 20815699773960 in words is "twenty trillion, eight hundred fifteen billion, six hundred ninety-nine million, seven hundred seventy-three thousand, nine hundred sixty".