221121031 has 4 divisors (see below), whose sum is σ = 232759000. Its totient is φ = 209483064.

The previous prime is 221121013. The next prime is 221121053. The reversal of 221121031 is 130121122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130121122 = 2 ⋅65060561.

It is a cyclic number.

It is not a de Polignac number, because 221121031 - 2⁷ = 221120903 is a prime.

It is a super-2 number, since 2×221121031² = 97789020701005922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121071) 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, 5818956 + ... + 5818993.

It is an arithmetic number, because the mean of its divisors is an integer number (58189750).

Almost surely, 2^221121031 is an apocalyptic number.

221121031 is a deficient number, since it is larger than the sum of its proper divisors (11637969).

221121031 is a wasteful number, since it uses less digits than its factorization.

221121031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11637968.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 221121031 is about 14870.1389031845. The cubic root of 221121031 is about 604.7047084790.

Adding to 221121031 its reverse (130121122), we get a palindrome (351242153).

Subtracting from 221121031 its reverse (130121122), we obtain a palindrome (90999909).

The spelling of 221121031 in words is "two hundred twenty-one million, one hundred twenty-one thousand, thirty-one".