21501332436881 has 64 divisors (see below), whose sum is σ = 25826082239232. Its totient is φ = 17680066560000.

The previous prime is 21501332436877. The next prime is 21501332436887. The reversal of 21501332436881 is 18863423310512.

It is a cyclic number.

It is not a de Polignac number, because 21501332436881 - 2² = 21501332436877 is a prime.

It is a super-2 number, since 2×21501332436881² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21501332436887) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 145627826 + ... + 145775396.

It is an arithmetic number, because the mean of its divisors is an integer number (403532534988).

Almost surely, 2^{21501332436881} is an apocalyptic number.

It is an amenable number.

21501332436881 is a deficient number, since it is larger than the sum of its proper divisors (4324749802351).

21501332436881 is a wasteful number, since it uses less digits than its factorization.

21501332436881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147954.

The product of its (nonzero) digits is 829440, while the sum is 47.

The spelling of 21501332436881 in words is "twenty-one trillion, five hundred one billion, three hundred thirty-two million, four hundred thirty-six thousand, eight hundred eighty-one".