31432221 has 18 divisors (see below), whose sum is σ = 46076030. Its totient is φ = 20646576.

The previous prime is 31432211. The next prime is 31432229. The reversal of 31432221 is 12223413.

It can be written as a sum of positive squares in only one way, i.e., 28836900 + 2595321 = 5370^2 + 1611^2 .

It is not a de Polignac number, because 31432221 - 2¹⁴ = 31415837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31432194 and 31432203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31432229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 175510 + ... + 175688.

Almost surely, 2^31432221 is an apocalyptic number.

It is an amenable number.

31432221 is a deficient number, since it is larger than the sum of its proper divisors (14643809).

31432221 is a wasteful number, since it uses less digits than its factorization.

31432221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473 (or 291 counting only the distinct ones).

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

The square root of 31432221 is about 5606.4445952850. Note that the first 3 decimals coincide. The cubic root of 31432221 is about 315.5913005356.

Adding to 31432221 its reverse (12223413), we get a palindrome (43655634).

The spelling of 31432221 in words is "thirty-one million, four hundred thirty-two thousand, two hundred twenty-one".