21513511223 has 16 divisors (see below), whose sum is σ = 22487801856. Its totient is φ = 20557912320.

The previous prime is 21513511199. The next prime is 21513511231. The reversal of 21513511223 is 32211531512.

It is a cyclic number.

It is not a de Polignac number, because 21513511223 - 2²² = 21509316919 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21513511192 and 21513511201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513511423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1117586 + ... + 1136672.

It is an arithmetic number, because the mean of its divisors is an integer number (1405487616).

Almost surely, 2^21513511223 is an apocalyptic number.

21513511223 is a deficient number, since it is larger than the sum of its proper divisors (974290633).

21513511223 is a wasteful number, since it uses less digits than its factorization.

21513511223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19574.

The product of its digits is 1800, while the sum is 26.

The spelling of 21513511223 in words is "twenty-one billion, five hundred thirteen million, five hundred eleven thousand, two hundred twenty-three".