21631648445 has 16 divisors (see below), whose sum is σ = 28609737408. Its totient is φ = 15569917440.

The previous prime is 21631648403. The next prime is 21631648457. The reversal of 21631648445 is 54484613612.

It is not a de Polignac number, because 21631648445 - 2²⁰ = 21630599869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21631648396 and 21631648405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2021999 + ... + 2032668.

It is an arithmetic number, because the mean of its divisors is an integer number (1788108588).

Almost surely, 2^21631648445 is an apocalyptic number.

It is an amenable number.

21631648445 is a deficient number, since it is larger than the sum of its proper divisors (6978088963).

21631648445 is a wasteful number, since it uses less digits than its factorization.

21631648445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4054780.

The product of its digits is 552960, while the sum is 44.

It can be divided in two parts, 21631 and 648445, that added together give a palindrome (670076).

The spelling of 21631648445 in words is "twenty-one billion, six hundred thirty-one million, six hundred forty-eight thousand, four hundred forty-five".