31628161 has 2 divisors, whose sum is σ = 31628162. Its totient is φ = 31628160.

The previous prime is 31628101. The next prime is 31628167. The reversal of 31628161 is 16182613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28090000 + 3538161 = 5300^2 + 1881^2 .

It is an emirp because it is prime and its reverse (16182613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31628161 - 2⁹ = 31627649 is a prime.

It is not a weakly prime, because it can be changed into another prime (31628167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15814080 + 15814081.

It is an arithmetic number, because the mean of its divisors is an integer number (15814081).

Almost surely, 2^31628161 is an apocalyptic number.

It is an amenable number.

31628161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31628161 is an equidigital number, since it uses as much as digits as its factorization.

31628161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 31628161 is about 5623.8919797592. The cubic root of 31628161 is about 316.2457129927.

The spelling of 31628161 in words is "thirty-one million, six hundred twenty-eight thousand, one hundred sixty-one".