21122242531 has 16 divisors (see below), whose sum is σ = 23164593760. Its totient is φ = 19140779520.

The previous prime is 21122242529. The next prime is 21122242573. The reversal of 21122242531 is 13524222112.

It is a cyclic number.

It is not a de Polignac number, because 21122242531 - 2¹ = 21122242529 is a prime.

It is a super-2 number, since 2×21122242531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21122242496 and 21122242505.

It is not an unprimeable number, because it can be changed into a prime (21122242511) 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, 389275 + ... + 440203.

It is an arithmetic number, because the mean of its divisors is an integer number (1447787110).

Almost surely, 2^21122242531 is an apocalyptic number.

21122242531 is a deficient number, since it is larger than the sum of its proper divisors (2042351229).

21122242531 is a wasteful number, since it uses less digits than its factorization.

21122242531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51526.

The product of its digits is 1920, while the sum is 25.

Adding to 21122242531 its reverse (13524222112), we get a palindrome (34646464643).

The spelling of 21122242531 in words is "twenty-one billion, one hundred twenty-two million, two hundred forty-two thousand, five hundred thirty-one".