21101231232131 has 4 divisors (see below), whose sum is σ = 21294820509600. Its totient is φ = 20907641954664.

The previous prime is 21101231232091. The next prime is 21101231232157. The reversal of 21101231232131 is 13123213210112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101231232131 is a prime.

It is a super-2 number, since 2×21101231232131² (a number of 27 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 = 21101231232097 and 21101231232106.

It is not an unprimeable number, because it can be changed into a prime (21101231232331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96794638571 + ... + 96794638788.

It is an arithmetic number, because the mean of its divisors is an integer number (5323705127400).

Almost surely, 2^{21101231232131} is an apocalyptic number.

21101231232131 is a deficient number, since it is larger than the sum of its proper divisors (193589277469).

21101231232131 is a wasteful number, since it uses less digits than its factorization.

21101231232131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193589277468.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21101231232131 its reverse (13123213210112), we get a palindrome (34224444442243).

The spelling of 21101231232131 in words is "twenty-one trillion, one hundred one billion, two hundred thirty-one million, two hundred thirty-two thousand, one hundred thirty-one".