21123040131 has 24 divisors (see below), whose sum is σ = 31372014960. Its totient is φ = 13689539136.

The previous prime is 21123040123. The next prime is 21123040139. The reversal of 21123040131 is 13104032112.

21123040131 is a `hidden beast` number, since 2 + 1 + 1 + 230 + 401 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (21123040123) and next prime (21123040139).

It is not a de Polignac number, because 21123040131 - 2³ = 21123040123 is a prime.

It is a super-2 number, since 2×21123040131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21123040139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 151141 + ... + 255126.

It is an arithmetic number, because the mean of its divisors is an integer number (1307167290).

Almost surely, 2^21123040131 is an apocalyptic number.

21123040131 is a deficient number, since it is larger than the sum of its proper divisors (10248974829).

21123040131 is a wasteful number, since it uses less digits than its factorization.

21123040131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406435 (or 406432 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21123040131 its reverse (13104032112), we get a palindrome (34227072243).

The spelling of 21123040131 in words is "twenty-one billion, one hundred twenty-three million, forty thousand, one hundred thirty-one".