21020212201 has 4 divisors (see below), whose sum is σ = 21206231892. Its totient is φ = 20834192512.

The previous prime is 21020212159. The next prime is 21020212219. The reversal of 21020212201 is 10221202012.

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 1342856025 + 19677356176 = 36645^2 + 140276^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020212201 - 2²³ = 21011823593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020212261) 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, 93009676 + ... + 93009901.

It is an arithmetic number, because the mean of its divisors is an integer number (5301557973).

Almost surely, 2^21020212201 is an apocalyptic number.

It is an amenable number.

21020212201 is a deficient number, since it is larger than the sum of its proper divisors (186019691).

21020212201 is a wasteful number, since it uses less digits than its factorization.

21020212201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186019690.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21020212201 its reverse (10221202012), we get a palindrome (31241414213).

The spelling of 21020212201 in words is "twenty-one billion, twenty million, two hundred twelve thousand, two hundred one".