31085869 has 2 divisors, whose sum is σ = 31085870. Its totient is φ = 31085868.

The previous prime is 31085833. The next prime is 31085897. The reversal of 31085869 is 96858013.

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., 16933225 + 14152644 = 4115^2 + 3762^2 .

It is a cyclic number.

It is not a de Polignac number, because 31085869 - 2¹³ = 31077677 is a prime.

It is a super-2 number, since 2×31085869² = 1932662502970322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31085669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15542934 + 15542935.

It is an arithmetic number, because the mean of its divisors is an integer number (15542935).

Almost surely, 2^31085869 is an apocalyptic number.

It is an amenable number.

31085869 is a deficient number, since it is larger than the sum of its proper divisors (1).

31085869 is an equidigital number, since it uses as much as digits as its factorization.

31085869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 31085869 is about 5575.4702940649. The cubic root of 31085869 is about 314.4278486092.

The spelling of 31085869 in words is "thirty-one million, eighty-five thousand, eight hundred sixty-nine".