21231112249 has 2 divisors, whose sum is σ = 21231112250. Its totient is φ = 21231112248.

The previous prime is 21231112241. The next prime is 21231112361. The reversal of 21231112249 is 94221113212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13465977849 + 7765134400 = 116043^2 + 88120^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231112249 - 2³ = 21231112241 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231112241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615556124 + 10615556125.

It is an arithmetic number, because the mean of its divisors is an integer number (10615556125).

Almost surely, 2^21231112249 is an apocalyptic number.

It is an amenable number.

21231112249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231112249 is an equidigital number, since it uses as much as digits as its factorization.

21231112249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The spelling of 21231112249 in words is "twenty-one billion, two hundred thirty-one million, one hundred twelve thousand, two hundred forty-nine".