21221431203 has 32 divisors (see below), whose sum is σ = 33148684800. Its totient is φ = 11822711040.

The previous prime is 21221431199. The next prime is 21221431223. The reversal of 21221431203 is 30213412212.

It is not a de Polignac number, because 21221431203 - 2² = 21221431199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21221431203.

It is not an unprimeable number, because it can be changed into a prime (21221431223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1393273 + ... + 1408421.

It is an arithmetic number, because the mean of its divisors is an integer number (1035896400).

Almost surely, 2^21221431203 is an apocalyptic number.

21221431203 is a deficient number, since it is larger than the sum of its proper divisors (11927253597).

21221431203 is a wasteful number, since it uses less digits than its factorization.

21221431203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16827.

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

Adding to 21221431203 its reverse (30213412212), we get a palindrome (51434843415).

The spelling of 21221431203 in words is "twenty-one billion, two hundred twenty-one million, four hundred thirty-one thousand, two hundred three".