21573465121 has 8 divisors (see below), whose sum is σ = 23234155560. Its totient is φ = 19912945152.

The previous prime is 21573465097. The next prime is 21573465131. The reversal of 21573465121 is 12156437512.

It can be written as a sum of positive squares in 4 ways, for example, as 7865738721 + 13707726400 = 88689^2 + 117080^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21573465121 - 2¹¹ = 21573463073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21573465131) 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, 363915 + ... + 419023.

It is an arithmetic number, because the mean of its divisors is an integer number (2904269445).

Almost surely, 2^21573465121 is an apocalyptic number.

It is an amenable number.

21573465121 is a deficient number, since it is larger than the sum of its proper divisors (1660690439).

21573465121 is a wasteful number, since it uses less digits than its factorization.

21573465121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85235.

The product of its digits is 50400, while the sum is 37.

The spelling of 21573465121 in words is "twenty-one billion, five hundred seventy-three million, four hundred sixty-five thousand, one hundred twenty-one".