21320023544 has 32 divisors (see below), whose sum is σ = 42336075600. Its totient is φ = 10030686720.

The previous prime is 21320023531. The next prime is 21320023547. The reversal of 21320023544 is 44532002312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320023547) 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, 690599 + ... + 720809.

Almost surely, 2^21320023544 is an apocalyptic number.

It is an amenable number.

21320023544 is a deficient number, since it is larger than the sum of its proper divisors (21016052056).

21320023544 is a wasteful number, since it uses less digits than its factorization.

21320023544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35423 (or 35419 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 26.

Adding to 21320023544 its reverse (44532002312), we get a palindrome (65852025856).

The spelling of 21320023544 in words is "twenty-one billion, three hundred twenty million, twenty-three thousand, five hundred forty-four".