21404322131 has 4 divisors (see below), whose sum is σ = 21558310200. Its totient is φ = 21250334064.

The previous prime is 21404322127. The next prime is 21404322143. The reversal of 21404322131 is 13122340412.

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 21404322131 - 2² = 21404322127 is a prime.

It is a super-2 number, since 2×21404322131² (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 = 21404322097 and 21404322106.

It is not an unprimeable number, because it can be changed into a prime (21403322131) 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, 76993826 + ... + 76994103.

It is an arithmetic number, because the mean of its divisors is an integer number (5389577550).

Almost surely, 2^21404322131 is an apocalyptic number.

21404322131 is a deficient number, since it is larger than the sum of its proper divisors (153988069).

21404322131 is a wasteful number, since it uses less digits than its factorization.

21404322131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153988068.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21404322131 its reverse (13122340412), we get a palindrome (34526662543).

The spelling of 21404322131 in words is "twenty-one billion, four hundred four million, three hundred twenty-two thousand, one hundred thirty-one".