21421211201 has 6 divisors (see below), whose sum is σ = 23195749590. Its totient is φ = 19773425568.

The previous prime is 21421211179. The next prime is 21421211237. The reversal of 21421211201 is 10211212412.

It can be written as a sum of positive squares in 3 ways, for example, as 2542176400 + 18879034801 = 50420^2 + 137401^2 .

It is not a de Polignac number, because 21421211201 - 2¹⁰ = 21421210177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21421211201.

It is not an unprimeable number, because it can be changed into a prime (21421211281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 63376196 + ... + 63376533.

It is an arithmetic number, because the mean of its divisors is an integer number (3865958265).

Almost surely, 2^21421211201 is an apocalyptic number.

It is an amenable number.

21421211201 is a deficient number, since it is larger than the sum of its proper divisors (1774538389).

21421211201 is a wasteful number, since it uses less digits than its factorization.

21421211201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126752755 (or 126752742 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21421211201 its reverse (10211212412), we get a palindrome (31632423613).

The spelling of 21421211201 in words is "twenty-one billion, four hundred twenty-one million, two hundred eleven thousand, two hundred one".