21520294677504 has 792 divisors, whose sum is σ = 76632866732448. Its totient is φ = 5779697172480.

The previous prime is 21520294677481. The next prime is 21520294677569. The reversal of 21520294677504 is 40577649202512.

It is a happy number.

21520294677504 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 0 + 29 + 46 + 77 + 504 = 666.

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, 9312112509 + ... + 9312114819.

Almost surely, 2^{21520294677504} is an apocalyptic number.

21520294677504 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 21520294677504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38316433366224).

21520294677504 is an abundant number, since it is smaller than the sum of its proper divisors (55112572054944).

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

21520294677504 is a wasteful number, since it uses less digits than its factorization.

21520294677504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3581 (or 3553 counting only the distinct ones).

The product of its (nonzero) digits is 8467200, while the sum is 54.

The spelling of 21520294677504 in words is "twenty-one trillion, five hundred twenty billion, two hundred ninety-four million, six hundred seventy-seven thousand, five hundred four".