921020221231 has 4 divisors (see below), whose sum is σ = 1004749332264. Its totient is φ = 837291110200.

The previous prime is 921020221181. The next prime is 921020221237. The reversal of 921020221231 is 132122020129.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 921020221231 - 2⁹ = 921020220719 is a prime.

It is a super-2 number, since 2×921020221231² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 921020221196 and 921020221205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921020221237) 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, 41864555500 + ... + 41864555521.

It is an arithmetic number, because the mean of its divisors is an integer number (251187333066).

Almost surely, 2^921020221231 is an apocalyptic number.

921020221231 is a deficient number, since it is larger than the sum of its proper divisors (83729111033).

921020221231 is a wasteful number, since it uses less digits than its factorization.

921020221231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83729111032.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 921020221231 in words is "nine hundred twenty-one billion, twenty million, two hundred twenty-one thousand, two hundred thirty-one".