221031423 has 20 divisors (see below), whose sum is σ = 332228248. Its totient is φ = 146441520.

The previous prime is 221031413. The next prime is 221031443. The reversal of 221031423 is 324130122.

221031423 is a `hidden beast` number, since 2 + 210 + 31 + 423 = 666.

It is not a de Polignac number, because 221031423 - 2¹² = 221027327 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221031396 and 221031405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221031413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4833 + ... + 21573.

Almost surely, 2^221031423 is an apocalyptic number.

221031423 is a deficient number, since it is larger than the sum of its proper divisors (111196825).

221031423 is a wasteful number, since it uses less digits than its factorization.

221031423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16916 (or 16907 counting only the distinct ones).

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

The square root of 221031423 is about 14867.1255796136. The cubic root of 221031423 is about 604.6230130978.

Adding to 221031423 its reverse (324130122), we get a palindrome (545161545).

It can be divided in two parts, 2210 and 31423, that added together give a palindrome (33633).

The spelling of 221031423 in words is "two hundred twenty-one million, thirty-one thousand, four hundred twenty-three".