31122421 has 4 divisors (see below), whose sum is σ = 33951744. Its totient is φ = 28293100.

The previous prime is 31122409. The next prime is 31122449. The reversal of 31122421 is 12422113.

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: 12422113 = 11 ⋅1129283.

It is not a de Polignac number, because 31122421 - 2⁷ = 31122293 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31122395 and 31122404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31122401) 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 3 ways as a sum of consecutive naturals, for example, 1414645 + ... + 1414666.

It is an arithmetic number, because the mean of its divisors is an integer number (8487936).

Almost surely, 2^31122421 is an apocalyptic number.

It is an amenable number.

31122421 is a deficient number, since it is larger than the sum of its proper divisors (2829323).

31122421 is a wasteful number, since it uses less digits than its factorization.

31122421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2829322.

The product of its digits is 96, while the sum is 16.

The square root of 31122421 is about 5578.7472608104. The cubic root of 31122421 is about 314.5510392571.

Adding to 31122421 its reverse (12422113), we get a palindrome (43544534).

The spelling of 31122421 in words is "thirty-one million, one hundred twenty-two thousand, four hundred twenty-one".