20977205760 has 720 divisors, whose sum is σ = 89564296536. Its totient is φ = 4508614656.

The previous prime is 20977205737. The next prime is 20977205803. The reversal of 20977205760 is 6750277902.

20977205760 is a `hidden beast` number, since 2 + 0 + 9 + 7 + 72 + 0 + 576 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 20971673856 + 5531904 = 144816^2 + 2352^2 .

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×20977205760² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 19191774 + ... + 19192866.

Almost surely, 2^20977205760 is an apocalyptic number.

20977205760 is a gapful number since it is divisible by the number (20) 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 20977205760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44782148268).

20977205760 is an abundant number, since it is smaller than the sum of its proper divisors (68587090776).

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

20977205760 is a wasteful number, since it uses less digits than its factorization.

20977205760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153 (or 1127 counting only the distinct ones).

The product of its (nonzero) digits is 370440, while the sum is 45.

The spelling of 20977205760 in words is "twenty billion, nine hundred seventy-seven million, two hundred five thousand, seven hundred sixty".