21282637178881 has 8 divisors (see below), whose sum is σ = 23122592879400. Its totient is φ = 19471657158912.

The previous prime is 21282637178861. The next prime is 21282637178893. The reversal of 21282637178881 is 18887173628212.

It can be written as a sum of positive squares in 4 ways, for example, as 1883536656400 + 19399100522481 = 1372420^2 + 4404441^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21282637178881 - 2¹³ = 21282637170689 is a prime.

It is a super-2 number, since 2×21282637178881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21282637178861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7243918606 + ... + 7243921543.

It is an arithmetic number, because the mean of its divisors is an integer number (2890324109925).

Almost surely, 2^{21282637178881} is an apocalyptic number.

It is an amenable number.

21282637178881 is a deficient number, since it is larger than the sum of its proper divisors (1839955700519).

21282637178881 is a wasteful number, since it uses less digits than its factorization.

21282637178881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14487840275.

The product of its digits is 28901376, while the sum is 64.

The spelling of 21282637178881 in words is "twenty-one trillion, two hundred eighty-two billion, six hundred thirty-seven million, one hundred seventy-eight thousand, eight hundred eighty-one".