21103123131 has 32 divisors (see below), whose sum is σ = 31386700800. Its totient is φ = 14013600480.

The previous prime is 21103123121. The next prime is 21103123141. The reversal of 21103123131 is 13132130112.

It is an interprime number because it is at equal distance from previous prime (21103123121) and next prime (21103123141).

It is not a de Polignac number, because 21103123131 - 2⁵ = 21103123099 is a prime.

It is a super-2 number, since 2×21103123131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21103123121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11278126 + ... + 11279996.

It is an arithmetic number, because the mean of its divisors is an integer number (980834400).

Almost surely, 2^21103123131 is an apocalyptic number.

21103123131 is a deficient number, since it is larger than the sum of its proper divisors (10283577669).

21103123131 is a wasteful number, since it uses less digits than its factorization.

21103123131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3296 (or 3290 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21103123131 its reverse (13132130112), we get a palindrome (34235253243).

The spelling of 21103123131 in words is "twenty-one billion, one hundred three million, one hundred twenty-three thousand, one hundred thirty-one".