221021021091 has 8 divisors (see below), whose sum is σ = 317363517520. Its totient is φ = 136012936032.

The previous prime is 221021021083. The next prime is 221021021113. The reversal of 221021021091 is 190120120122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221021021091 - 2³ = 221021021083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221021021591) 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, 2833602796 + ... + 2833602873.

It is an arithmetic number, because the mean of its divisors is an integer number (39670439690).

Almost surely, 2^221021021091 is an apocalyptic number.

221021021091 is a deficient number, since it is larger than the sum of its proper divisors (96342496429).

221021021091 is a wasteful number, since it uses less digits than its factorization.

221021021091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5667205685.

The product of its (nonzero) digits is 144, while the sum is 21.

The spelling of 221021021091 in words is "two hundred twenty-one billion, twenty-one million, twenty-one thousand, ninety-one".