221001031 has 2 divisors, whose sum is σ = 221001032. Its totient is φ = 221001030.

The previous prime is 221000981. The next prime is 221001049. The reversal of 221001031 is 130100122.

221001031 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221001031 - 2¹¹ = 220998983 is a prime.

It is a super-2 number, since 2×221001031² = 97682911406125922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221000999 and 221001017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221001091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110500515 + 110500516.

It is an arithmetic number, because the mean of its divisors is an integer number (110500516).

Almost surely, 2^221001031 is an apocalyptic number.

221001031 is a deficient number, since it is larger than the sum of its proper divisors (1).

221001031 is an equidigital number, since it uses as much as digits as its factorization.

221001031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 221001031 is about 14866.1034235606. The cubic root of 221001031 is about 604.5952997759.

Adding to 221001031 its reverse (130100122), we get a palindrome (351101153).

Subtracting from 221001031 its reverse (130100122), we obtain a palindrome (90900909).

The spelling of 221001031 in words is "two hundred twenty-one million, one thousand, thirty-one".