31456121 has 2 divisors, whose sum is σ = 31456122. Its totient is φ = 31456120.

The previous prime is 31456099. The next prime is 31456123. The reversal of 31456121 is 12165413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21752896 + 9703225 = 4664^2 + 3115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31456121 is a prime.

It is a Sophie Germain prime.

Together with 31456123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p_1942322 and since 31456121 and 1942322 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (31456123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15728060 + 15728061.

It is an arithmetic number, because the mean of its divisors is an integer number (15728061).

Almost surely, 2^31456121 is an apocalyptic number.

It is an amenable number.

31456121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31456121 is an equidigital number, since it uses as much as digits as its factorization.

31456121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 31456121 is about 5608.5756658888. The cubic root of 31456121 is about 315.6712685952.

The spelling of 31456121 in words is "thirty-one million, four hundred fifty-six thousand, one hundred twenty-one".