202201020100021 has 4 divisors (see below), whose sum is σ = 202218975978444. Its totient is φ = 202183064221600.

The previous prime is 202201020099959. The next prime is 202201020100049. The reversal of 202201020100021 is 120001020102202.

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 190518364459921 + 11682655640100 = 13802839^2 + 3417990^2 .

It is a cyclic number.

It is not a de Polignac number, because 202201020100021 - 2⁷ = 202201020099893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202201020099974 and 202201020100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202201020100081) 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, 8977922320 + ... + 8977944841.

It is an arithmetic number, because the mean of its divisors is an integer number (50554743994611).

Almost surely, 2^{202201020100021} is an apocalyptic number.

It is an amenable number.

202201020100021 is a deficient number, since it is larger than the sum of its proper divisors (17955878423).

202201020100021 is a wasteful number, since it uses less digits than its factorization.

202201020100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17955878422.

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

Adding to 202201020100021 its reverse (120001020102202), we get a palindrome (322202040202223).

The spelling of 202201020100021 in words is "two hundred two trillion, two hundred one billion, twenty million, one hundred thousand, twenty-one".