21311233131 has 8 divisors (see below), whose sum is σ = 29910502720. Its totient is φ = 13459726152.

The previous prime is 21311233127. The next prime is 21311233159. The reversal of 21311233131 is 13133211312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21311233131 - 2² = 21311233127 is a prime.

It is a super-2 number, since 2×21311233131² (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 = 21311233098 and 21311233107.

It is not an unprimeable number, because it can be changed into a prime (21311233331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186940585 + ... + 186940698.

It is an arithmetic number, because the mean of its divisors is an integer number (3738812840).

Almost surely, 2^21311233131 is an apocalyptic number.

21311233131 is a deficient number, since it is larger than the sum of its proper divisors (8599269589).

21311233131 is a wasteful number, since it uses less digits than its factorization.

21311233131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373881305.

The product of its digits is 324, while the sum is 21.

Adding to 21311233131 its reverse (13133211312), we get a palindrome (34444444443).

The spelling of 21311233131 in words is "twenty-one billion, three hundred eleven million, two hundred thirty-three thousand, one hundred thirty-one".