31866121 has 6 divisors (see below), whose sum is σ = 37068810. Its totient is φ = 27313776.

The previous prime is 31866119. The next prime is 31866127. The reversal of 31866121 is 12166813.

It can be written as a sum of positive squares in only one way, i.e., 31753225 + 112896 = 5635^2 + 336^2 .

It is not a de Polignac number, because 31866121 - 2¹ = 31866119 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31866121.

It is not an unprimeable number, because it can be changed into a prime (31866127) 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 5 ways as a sum of consecutive naturals, for example, 325116 + ... + 325213.

It is an arithmetic number, because the mean of its divisors is an integer number (6178135).

Almost surely, 2^31866121 is an apocalyptic number.

It is an amenable number.

31866121 is a deficient number, since it is larger than the sum of its proper divisors (5202689).

31866121 is an equidigital number, since it uses as much as digits as its factorization.

31866121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 650343 (or 650336 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 31866121 is about 5645.0085030937. The cubic root of 31866121 is about 317.0368422053.

The spelling of 31866121 in words is "thirty-one million, eight hundred sixty-six thousand, one hundred twenty-one".