21881861279 has 8 divisors (see below), whose sum is σ = 23007549312. Its totient is φ = 20770698520.

The previous prime is 21881861263. The next prime is 21881861311. The reversal of 21881861279 is 97216818812.

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 21881861279 - 2⁴ = 21881861263 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21881861279.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21881861249) 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, 3628229 + ... + 3634254.

It is an arithmetic number, because the mean of its divisors is an integer number (2875943664).

Almost surely, 2^21881861279 is an apocalyptic number.

21881861279 is a deficient number, since it is larger than the sum of its proper divisors (1125688033).

21881861279 is a wasteful number, since it uses less digits than its factorization.

21881861279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7262637.

The product of its digits is 774144, while the sum is 53.

The spelling of 21881861279 in words is "twenty-one billion, eight hundred eighty-one million, eight hundred sixty-one thousand, two hundred seventy-nine".