221423031 has 8 divisors (see below), whose sum is σ = 328034160. Its totient is φ = 147615336.

The previous prime is 221423023. The next prime is 221423071. The reversal of 221423031 is 130324122.

It is not a de Polignac number, because 221423031 - 2³ = 221423023 is a prime.

It is a super-2 number, since 2×221423031² = 98056317314453922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221422995 and 221423013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221423071) 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, 4100400 + ... + 4100453.

It is an arithmetic number, because the mean of its divisors is an integer number (41004270).

Almost surely, 2^221423031 is an apocalyptic number.

221423031 is a deficient number, since it is larger than the sum of its proper divisors (106611129).

221423031 is an equidigital number, since it uses as much as digits as its factorization.

221423031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8200862 (or 8200856 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 221423031 is about 14880.2900173350. The cubic root of 221423031 is about 604.9798786651.

Adding to 221423031 its reverse (130324122), we get a palindrome (351747153).

The spelling of 221423031 in words is "two hundred twenty-one million, four hundred twenty-three thousand, thirty-one".