31221345 has 8 divisors (see below), whose sum is σ = 49954176. Its totient is φ = 16651376.

The previous prime is 31221343. The next prime is 31221347. The reversal of 31221345 is 54312213.

It is an interprime number because it is at equal distance from previous prime (31221343) and next prime (31221347).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31221345 - 2¹ = 31221343 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31221343) 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 7 ways as a sum of consecutive naturals, for example, 1040697 + ... + 1040726.

It is an arithmetic number, because the mean of its divisors is an integer number (6244272).

Almost surely, 2^31221345 is an apocalyptic number.

It is an amenable number.

31221345 is a deficient number, since it is larger than the sum of its proper divisors (18732831).

31221345 is a wasteful number, since it uses less digits than its factorization.

31221345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2081431.

The product of its digits is 720, while the sum is 21.

The square root of 31221345 is about 5587.6063748263. The cubic root of 31221345 is about 314.8839582649.

Adding to 31221345 its reverse (54312213), we get a palindrome (85533558).

The spelling of 31221345 in words is "thirty-one million, two hundred twenty-one thousand, three hundred forty-five".