31042221 has 32 divisors (see below), whose sum is σ = 50699520. Its totient is φ = 16490496.

The previous prime is 31042217. The next prime is 31042241. The reversal of 31042221 is 12224013.

It is not a de Polignac number, because 31042221 - 2² = 31042217 is a prime.

It is a super-2 number, since 2×31042221² = 1927238969225682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31042221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31042241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31285 + ... + 32261.

It is an arithmetic number, because the mean of its divisors is an integer number (1584360).

Almost surely, 2^31042221 is an apocalyptic number.

It is an amenable number.

31042221 is a deficient number, since it is larger than the sum of its proper divisors (19657299).

31042221 is a wasteful number, since it uses less digits than its factorization.

31042221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1093.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31042221 is about 5571.5546304420. The cubic root of 31042221 is about 314.2806158461.

Adding to 31042221 its reverse (12224013), we get a palindrome (43266234).

The spelling of 31042221 in words is "thirty-one million, forty-two thousand, two hundred twenty-one".