21230404131 has 4 divisors (see below), whose sum is σ = 28307205512. Its totient is φ = 14153602752.

The previous prime is 21230404123. The next prime is 21230404171. The reversal of 21230404131 is 13140403212.

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

It is not a de Polignac number, because 21230404131 - 2³ = 21230404123 is a prime.

It is a super-2 number, since 2×21230404131² (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 = 21230404098 and 21230404107.

It is not an unprimeable number, because it can be changed into a prime (21230404171) 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, 3538400686 + ... + 3538400691.

It is an arithmetic number, because the mean of its divisors is an integer number (7076801378).

Almost surely, 2^21230404131 is an apocalyptic number.

21230404131 is a deficient number, since it is larger than the sum of its proper divisors (7076801381).

21230404131 is an equidigital number, since it uses as much as digits as its factorization.

21230404131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7076801380.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21230404131 its reverse (13140403212), we get a palindrome (34370807343).

The spelling of 21230404131 in words is "twenty-one billion, two hundred thirty million, four hundred four thousand, one hundred thirty-one".