21120242331 has 16 divisors (see below), whose sum is σ = 28649934720. Its totient is φ = 13835561280.

The previous prime is 21120242327. The next prime is 21120242393. The reversal of 21120242331 is 13324202112.

It is not a de Polignac number, because 21120242331 - 2² = 21120242327 is a prime.

It is a super-2 number, since 2×21120242331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21120242298 and 21120242307.

It is not an unprimeable number, because it can be changed into a prime (21120292331) 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, 407616 + ... + 456498.

It is an arithmetic number, because the mean of its divisors is an integer number (1790620920).

Almost surely, 2^21120242331 is an apocalyptic number.

21120242331 is a deficient number, since it is larger than the sum of its proper divisors (7529692389).

21120242331 is a wasteful number, since it uses less digits than its factorization.

21120242331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51386.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21120242331 its reverse (13324202112), we get a palindrome (34444444443).

The spelling of 21120242331 in words is "twenty-one billion, one hundred twenty million, two hundred forty-two thousand, three hundred thirty-one".