21323012131 has 4 divisors (see below), whose sum is σ = 22010851264. Its totient is φ = 20635173000.

The previous prime is 21323012119. The next prime is 21323012177. The reversal of 21323012131 is 13121032312.

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

It is a cyclic number.

It is not a de Polignac number, because 21323012131 - 2⁷ = 21323012003 is a prime.

It is a super-2 number, since 2×21323012131² (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 = 21323012099 and 21323012108.

It is not an unprimeable number, because it can be changed into a prime (21323012101) 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 3 ways as a sum of consecutive naturals, for example, 343919520 + ... + 343919581.

It is an arithmetic number, because the mean of its divisors is an integer number (5502712816).

Almost surely, 2^21323012131 is an apocalyptic number.

21323012131 is a deficient number, since it is larger than the sum of its proper divisors (687839133).

21323012131 is an equidigital number, since it uses as much as digits as its factorization.

21323012131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687839132.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21323012131 its reverse (13121032312), we get a palindrome (34444044443).

The spelling of 21323012131 in words is "twenty-one billion, three hundred twenty-three million, twelve thousand, one hundred thirty-one".