31149221 has 2 divisors, whose sum is σ = 31149222. Its totient is φ = 31149220.

The previous prime is 31149211. The next prime is 31149233. The reversal of 31149221 is 12294113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30129121 + 1020100 = 5489^2 + 1010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31149221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31149211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15574610 + 15574611.

It is an arithmetic number, because the mean of its divisors is an integer number (15574611).

Almost surely, 2^31149221 is an apocalyptic number.

It is an amenable number.

31149221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31149221 is an equidigital number, since it uses as much as digits as its factorization.

31149221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

The square root of 31149221 is about 5581.1487168862. The cubic root of 31149221 is about 314.6413016147.

The spelling of 31149221 in words is "thirty-one million, one hundred forty-nine thousand, two hundred twenty-one".