202001010020021 has 4 divisors (see below), whose sum is σ = 202198856260044. Its totient is φ = 201803163780000.

The previous prime is 202001010019981. The next prime is 202001010020077. The reversal of 202001010020021 is 120020010100202.

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 164518820067121 + 37482189952900 = 12826489^2 + 6122270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-202001010020021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 202001010019984 and 202001010020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202001010020521) 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, 98923118480 + ... + 98923120521.

It is an arithmetic number, because the mean of its divisors is an integer number (50549714065011).

Almost surely, 2^{202001010020021} is an apocalyptic number.

It is an amenable number.

202001010020021 is a deficient number, since it is larger than the sum of its proper divisors (197846240023).

202001010020021 is a wasteful number, since it uses less digits than its factorization.

202001010020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197846240022.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 202001010020021 its reverse (120020010100202), we get a palindrome (322021020120223).

The spelling of 202001010020021 in words is "two hundred two trillion, one billion, ten million, twenty thousand, twenty-one".