221020002128 has 40 divisors (see below), whose sum is σ = 443461664256. Its totient is φ = 106601212800.

The previous prime is 221020002121. The next prime is 221020002163. The reversal of 221020002128 is 821200020122.

It is a happy number.

It is a super-2 number, since 2×221020002128² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020002121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 562151 + ... + 870662.

Almost surely, 2^221020002128 is an apocalyptic number.

It is an amenable number.

221020002128 is an abundant number, since it is smaller than the sum of its proper divisors (222441662128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221020002128 is a wasteful number, since it uses less digits than its factorization.

221020002128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433163 (or 1433157 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The spelling of 221020002128 in words is "two hundred twenty-one billion, twenty million, two thousand, one hundred twenty-eight".