21130561201 has 4 divisors (see below), whose sum is σ = 21284799012. Its totient is φ = 20976323392.

The previous prime is 21130561169. The next prime is 21130561211. The reversal of 21130561201 is 10216503112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14128888225 + 7001672976 = 118865^2 + 83676^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130561201 - 2⁵ = 21130561169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21130561211) 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, 77118700 + ... + 77118973.

It is an arithmetic number, because the mean of its divisors is an integer number (5321199753).

Almost surely, 2^21130561201 is an apocalyptic number.

It is an amenable number.

21130561201 is a deficient number, since it is larger than the sum of its proper divisors (154237811).

21130561201 is a wasteful number, since it uses less digits than its factorization.

21130561201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154237810.

The product of its (nonzero) digits is 360, while the sum is 22.

The spelling of 21130561201 in words is "twenty-one billion, one hundred thirty million, five hundred sixty-one thousand, two hundred one".