21131312403 has 8 divisors (see below), whose sum is σ = 29657982400. Its totient is φ = 13346092008.

The previous prime is 21131312333. The next prime is 21131312417. The reversal of 21131312403 is 30421313112.

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

It is not a de Polignac number, because 21131312403 - 2¹⁶ = 21131246867 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21131312403.

It is not an unprimeable number, because it can be changed into a prime (21131312473) 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, 185362333 + ... + 185362446.

It is an arithmetic number, because the mean of its divisors is an integer number (3707247800).

Almost surely, 2^21131312403 is an apocalyptic number.

21131312403 is a deficient number, since it is larger than the sum of its proper divisors (8526669997).

21131312403 is a wasteful number, since it uses less digits than its factorization.

21131312403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370724801.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21131312403 its reverse (30421313112), we get a palindrome (51552625515).

The spelling of 21131312403 in words is "twenty-one billion, one hundred thirty-one million, three hundred twelve thousand, four hundred three".