21311221403 has 16 divisors (see below), whose sum is σ = 22633803360. Its totient is φ = 19996416000.

The previous prime is 21311221397. The next prime is 21311221441. The reversal of 21311221403 is 30412211312.

It is a cyclic number.

It is not a de Polignac number, because 21311221403 - 2¹⁰ = 21311220379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311221453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13495868 + ... + 13497446.

It is an arithmetic number, because the mean of its divisors is an integer number (1414612710).

Almost surely, 2^21311221403 is an apocalyptic number.

21311221403 is a deficient number, since it is larger than the sum of its proper divisors (1322581957).

21311221403 is a wasteful number, since it uses less digits than its factorization.

21311221403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3518.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21311221403 its reverse (30412211312), we get a palindrome (51723432715).

The spelling of 21311221403 in words is "twenty-one billion, three hundred eleven million, two hundred twenty-one thousand, four hundred three".