20956315680 has 192 divisors, whose sum is σ = 76536472320. Its totient is φ = 5345353728.

The previous prime is 20956315643. The next prime is 20956315717. The reversal of 20956315680 is 8651365902.

20956315680 is a `hidden beast` number, since 2 + 0 + 9 + 5 + 631 + 5 + 6 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (20956315643) and next prime (20956315717).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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 31 ways as a sum of consecutive naturals, for example, 6097 + ... + 204816.

It is an arithmetic number, because the mean of its divisors is an integer number (398627460).

Almost surely, 2^20956315680 is an apocalyptic number.

20956315680 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 20956315680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38268236160).

20956315680 is an abundant number, since it is smaller than the sum of its proper divisors (55580156640).

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

20956315680 is a wasteful number, since it uses less digits than its factorization.

20956315680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210960 (or 210946 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 20956315680 in words is "twenty billion, nine hundred fifty-six million, three hundred fifteen thousand, six hundred eighty".