21954494772864 has 960 divisors, whose sum is σ = 71398716840000. Its totient is φ = 6671512387584.

The previous prime is 21954494772863. The next prime is 21954494772871. The reversal of 21954494772864 is 46827749445912.

21954494772864 is a `hidden beast` number, since 2 + 1 + 9 + 5 + 4 + 494 + 7 + 72 + 8 + 64 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21954494772792 and 21954494772801.

It is not an unprimeable number, because it can be changed into a prime (21954494772863) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 110324094237 + ... + 110324094435.

It is an arithmetic number, because the mean of its divisors is an integer number (74373663375).

Almost surely, 2^{21954494772864} is an apocalyptic number.

21954494772864 is a gapful number since it is divisible by the number (24) 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 21954494772864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35699358420000).

21954494772864 is an abundant number, since it is smaller than the sum of its proper divisors (49444222067136).

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

21954494772864 is a wasteful number, since it uses less digits than its factorization.

21954494772864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507 (or 383 counting only the distinct ones).

The product of its digits is 975421440, while the sum is 72.

The spelling of 21954494772864 in words is "twenty-one trillion, nine hundred fifty-four billion, four hundred ninety-four million, seven hundred seventy-two thousand, eight hundred sixty-four".