21302123131 has 4 divisors (see below), whose sum is σ = 21469856512. Its totient is φ = 21134389752.

The previous prime is 21302123123. The next prime is 21302123189. The reversal of 21302123131 is 13132120312.

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 21302123131 - 2³ = 21302123123 is a prime.

It is a super-2 number, since 2×21302123131² (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 = 21302123099 and 21302123108.

It is not an unprimeable number, because it can be changed into a prime (21302121131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83866500 + ... + 83866753.

It is an arithmetic number, because the mean of its divisors is an integer number (5367464128).

Almost surely, 2^21302123131 is an apocalyptic number.

21302123131 is a deficient number, since it is larger than the sum of its proper divisors (167733381).

21302123131 is a wasteful number, since it uses less digits than its factorization.

21302123131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167733380.

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

Adding to 21302123131 its reverse (13132120312), we get a palindrome (34434243443).

The spelling of 21302123131 in words is "twenty-one billion, three hundred two million, one hundred twenty-three thousand, one hundred thirty-one".