21488931841 has 4 divisors (see below), whose sum is σ = 23141926612. Its totient is φ = 19835937072.

The previous prime is 21488931839. The next prime is 21488931851. The reversal of 21488931841 is 14813988412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5098531216 + 16390400625 = 71404^2 + 128025^2 .

It is a cyclic number.

It is not a de Polignac number, because 21488931841 - 2¹ = 21488931839 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21488931851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 826497366 + ... + 826497391.

It is an arithmetic number, because the mean of its divisors is an integer number (5785481653).

Almost surely, 2^21488931841 is an apocalyptic number.

It is an amenable number.

21488931841 is a deficient number, since it is larger than the sum of its proper divisors (1652994771).

21488931841 is a wasteful number, since it uses less digits than its factorization.

21488931841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1652994770.

The product of its digits is 442368, while the sum is 49.

The spelling of 21488931841 in words is "twenty-one billion, four hundred eighty-eight million, nine hundred thirty-one thousand, eight hundred forty-one".