31409221 has 4 divisors (see below), whose sum is σ = 32139712. Its totient is φ = 30678732.

The previous prime is 31409201. The next prime is 31409227. The reversal of 31409221 is 12290413.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12290413 = 67 ⋅183439.

It is a cyclic number.

It is not a de Polignac number, because 31409221 - 2¹⁵ = 31376453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31409192 and 31409201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31409227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 365181 + ... + 365266.

It is an arithmetic number, because the mean of its divisors is an integer number (8034928).

Almost surely, 2^31409221 is an apocalyptic number.

It is an amenable number.

31409221 is a deficient number, since it is larger than the sum of its proper divisors (730491).

31409221 is an equidigital number, since it uses as much as digits as its factorization.

31409221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730490.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 31409221 is about 5604.3930090599. The cubic root of 31409221 is about 315.5143055407.

Adding to 31409221 its reverse (12290413), we get a palindrome (43699634).

The spelling of 31409221 in words is "thirty-one million, four hundred nine thousand, two hundred twenty-one".