31444157 has 2 divisors, whose sum is σ = 31444158. Its totient is φ = 31444156.

The previous prime is 31444121. The next prime is 31444159. The reversal of 31444157 is 75144413.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31292836 + 151321 = 5594^2 + 389^2 .

It is an emirp because it is prime and its reverse (75144413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31444157 - 2¹⁰ = 31443133 is a prime.

Together with 31444159, 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 (31444159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15722078 + 15722079.

It is an arithmetic number, because the mean of its divisors is an integer number (15722079).

Almost surely, 2^31444157 is an apocalyptic number.

It is an amenable number.

31444157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31444157 is an equidigital number, since it uses as much as digits as its factorization.

31444157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 31444157 is about 5607.5089834970. The cubic root of 31444157 is about 315.6312427873.

The spelling of 31444157 in words is "thirty-one million, four hundred forty-four thousand, one hundred fifty-seven".