21197563435776 has 1728 divisors, whose sum is σ = 75920773533696. Its totient is φ = 5194815897600.

The previous prime is 21197563435709. The next prime is 21197563435831. The reversal of 21197563435776 is 67753436579112.

It is a super-2 number, since 2×21197563435776² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 45390927895 + ... + 45390928361.

It is an arithmetic number, because the mean of its divisors is an integer number (43935632832).

Almost surely, 2^{21197563435776} is an apocalyptic number.

21197563435776 is a gapful number since it is divisible by the number (26) 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 21197563435776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37960386766848).

21197563435776 is an abundant number, since it is smaller than the sum of its proper divisors (54723210097920).

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

21197563435776 is a wasteful number, since it uses less digits than its factorization.

21197563435776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658 (or 637 counting only the distinct ones).

The product of its digits is 200037600, while the sum is 66.

The spelling of 21197563435776 in words is "twenty-one trillion, one hundred ninety-seven billion, five hundred sixty-three million, four hundred thirty-five thousand, seven hundred seventy-six".