21723044057 has 64 divisors (see below), whose sum is σ = 27646230528. Its totient is φ = 16765056000.

The previous prime is 21723044029. The next prime is 21723044087. The reversal of 21723044057 is 75044032712.

It is not a de Polignac number, because 21723044057 - 2⁸ = 21723043801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21723044027) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 21919832 + ... + 21920822.

It is an arithmetic number, because the mean of its divisors is an integer number (431972352).

Almost surely, 2^21723044057 is an apocalyptic number.

It is an amenable number.

21723044057 is a deficient number, since it is larger than the sum of its proper divisors (5923186471).

21723044057 is a wasteful number, since it uses less digits than its factorization.

21723044057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1230.

The product of its (nonzero) digits is 47040, while the sum is 35.

Adding to 21723044057 its reverse (75044032712), we get a palindrome (96767076769).

The spelling of 21723044057 in words is "twenty-one billion, seven hundred twenty-three million, forty-four thousand, fifty-seven".