221000202120021 has 16 divisors (see below), whose sum is σ = 312261811236864. Its totient is φ = 138550559757824.

The previous prime is 221000202120011. The next prime is 221000202120037. The reversal of 221000202120021 is 120021202000122.

It is a cyclic number.

It is not a de Polignac number, because 221000202120021 - 2⁵ = 221000202119989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000202120011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1816090581 + ... + 1816212266.

It is an arithmetic number, because the mean of its divisors is an integer number (19516363202304).

Almost surely, 2^{221000202120021} is an apocalyptic number.

It is an amenable number.

221000202120021 is a deficient number, since it is larger than the sum of its proper divisors (91261609116843).

221000202120021 is a wasteful number, since it uses less digits than its factorization.

221000202120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3632304060.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221000202120021 its reverse (120021202000122), we get a palindrome (341021404120143).

The spelling of 221000202120021 in words is "two hundred twenty-one trillion, two hundred two million, one hundred twenty thousand, twenty-one".