21115352231 has 16 divisors (see below), whose sum is σ = 22931657280. Its totient is φ = 19364075520.

The previous prime is 21115352201. The next prime is 21115352263. The reversal of 21115352231 is 13225351112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21115352231 is a prime.

It is a super-2 number, since 2×21115352231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21115352231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115352201) 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, 545150 + ... + 582596.

It is an arithmetic number, because the mean of its divisors is an integer number (1433228580).

Almost surely, 2^21115352231 is an apocalyptic number.

21115352231 is a deficient number, since it is larger than the sum of its proper divisors (1816305049).

21115352231 is a wasteful number, since it uses less digits than its factorization.

21115352231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38314.

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

The spelling of 21115352231 in words is "twenty-one billion, one hundred fifteen million, three hundred fifty-two thousand, two hundred thirty-one".