31445861 has 2 divisors, whose sum is σ = 31445862. Its totient is φ = 31445860.

The previous prime is 31445851. The next prime is 31445863. The reversal of 31445861 is 16854413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22743361 + 8702500 = 4769^2 + 2950^2 .

It is a cyclic number.

It is not a de Polignac number, because 31445861 - 2¹⁰ = 31444837 is a prime.

Together with 31445863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31445863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15722930 + 15722931.

It is an arithmetic number, because the mean of its divisors is an integer number (15722931).

Almost surely, 2^31445861 is an apocalyptic number.

It is an amenable number.

31445861 is a deficient number, since it is larger than the sum of its proper divisors (1).

31445861 is an equidigital number, since it uses as much as digits as its factorization.

31445861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 32.

The square root of 31445861 is about 5607.6609205622. The cubic root of 31445861 is about 315.6369441743.

The spelling of 31445861 in words is "thirty-one million, four hundred forty-five thousand, eight hundred sixty-one".