21265944201 has 20 divisors (see below), whose sum is σ = 31779163152. Its totient is φ = 14172155928.

The previous prime is 21265944197. The next prime is 21265944223. The reversal of 21265944201 is 10244956212.

It is a happy number.

21265944201 is a `hidden beast` number, since 2 + 1 + 26 + 594 + 42 + 0 + 1 = 666.

It is not a de Polignac number, because 21265944201 - 2² = 21265944197 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21265944281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 184110 + ... + 276456.

Almost surely, 2^21265944201 is an apocalyptic number.

It is an amenable number.

21265944201 is a deficient number, since it is larger than the sum of its proper divisors (10513218951).

21265944201 is an equidigital number, since it uses as much as digits as its factorization.

21265944201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95202 (or 95193 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 21265944201 in words is "twenty-one billion, two hundred sixty-five million, nine hundred forty-four thousand, two hundred one".