21545321304 has 32 divisors (see below), whose sum is σ = 58006635120. Its totient is φ = 6629329536.

The previous prime is 21545321299. The next prime is 21545321309. The reversal of 21545321304 is 40312354512.

It is an interprime number because it is at equal distance from previous prime (21545321299) and next prime (21545321309).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21545321309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34527447 + ... + 34528070.

Almost surely, 2^21545321304 is an apocalyptic number.

21545321304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21545321304 is an abundant number, since it is smaller than the sum of its proper divisors (36461313816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21545321304 is a wasteful number, since it uses less digits than its factorization.

21545321304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69055539 (or 69055535 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

Adding to 21545321304 its reverse (40312354512), we get a palindrome (61857675816).

The spelling of 21545321304 in words is "twenty-one billion, five hundred forty-five million, three hundred twenty-one thousand, three hundred four".