31255121 has 4 divisors (see below), whose sum is σ = 32099892. Its totient is φ = 30410352.

The previous prime is 31255117. The next prime is 31255151. The reversal of 31255121 is 12155213.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12155213 = 7 ⋅1736459.

It can be written as a sum of positive squares in 2 ways, for example, as 29593600 + 1661521 = 5440^2 + 1289^2 .

It is a cyclic number.

It is not a de Polignac number, because 31255121 - 2² = 31255117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31255093 and 31255102.

It is not an unprimeable number, because it can be changed into a prime (31255111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 422330 + ... + 422403.

It is an arithmetic number, because the mean of its divisors is an integer number (8024973).

Almost surely, 2^31255121 is an apocalyptic number.

It is an amenable number.

31255121 is a deficient number, since it is larger than the sum of its proper divisors (844771).

31255121 is an equidigital number, since it uses as much as digits as its factorization.

31255121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844770.

The product of its digits is 300, while the sum is 20.

The square root of 31255121 is about 5590.6279611507. The cubic root of 31255121 is about 314.9974670158.

The spelling of 31255121 in words is "thirty-one million, two hundred fifty-five thousand, one hundred twenty-one".