31499161 has 2 divisors, whose sum is σ = 31499162. Its totient is φ = 31499160.

The previous prime is 31499159. The next prime is 31499183. The reversal of 31499161 is 16199413.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19527561 + 11971600 = 4419^2 + 3460^2 .

It is an emirp because it is prime and its reverse (16199413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31499161 - 2¹ = 31499159 is a prime.

Together with 31499159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31499561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15749580 + 15749581.

It is an arithmetic number, because the mean of its divisors is an integer number (15749581).

Almost surely, 2^31499161 is an apocalyptic number.

It is an amenable number.

31499161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31499161 is an equidigital number, since it uses as much as digits as its factorization.

31499161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 31499161 is about 5612.4113356026. The cubic root of 31499161 is about 315.8151759290.

The spelling of 31499161 in words is "thirty-one million, four hundred ninety-nine thousand, one hundred sixty-one".