31389697 has 2 divisors, whose sum is σ = 31389698. Its totient is φ = 31389696.

The previous prime is 31389671. The next prime is 31389707. The reversal of 31389697 is 79698313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31371201 + 18496 = 5601^2 + 136^2 .

It is an emirp because it is prime and its reverse (79698313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31389697 - 2⁷ = 31389569 is a prime.

It is not a weakly prime, because it can be changed into another prime (31389637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15694848 + 15694849.

It is an arithmetic number, because the mean of its divisors is an integer number (15694849).

Almost surely, 2^31389697 is an apocalyptic number.

It is an amenable number.

31389697 is a deficient number, since it is larger than the sum of its proper divisors (1).

31389697 is an equidigital number, since it uses as much as digits as its factorization.

31389697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 46.

The square root of 31389697 is about 5602.6508904268. The cubic root of 31389697 is about 315.4489173318.

The spelling of 31389697 in words is "thirty-one million, three hundred eighty-nine thousand, six hundred ninety-seven".