21379013881 has 4 divisors (see below), whose sum is σ = 21384259200. Its totient is φ = 21373768564.

The previous prime is 21379013839. The next prime is 21379013893. The reversal of 21379013881 is 18831097312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21379013881 - 2¹³ = 21379005689 is a prime.

It is a super-2 number, since 2×21379013881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21379019881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2616541 + ... + 2624698.

It is an arithmetic number, because the mean of its divisors is an integer number (5346064800).

Almost surely, 2^21379013881 is an apocalyptic number.

It is an amenable number.

21379013881 is a deficient number, since it is larger than the sum of its proper divisors (5245319).

21379013881 is an equidigital number, since it uses as much as digits as its factorization.

21379013881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5245318.

The product of its (nonzero) digits is 72576, while the sum is 43.

The spelling of 21379013881 in words is "twenty-one billion, three hundred seventy-nine million, thirteen thousand, eight hundred eighty-one".