31481887 has 2 divisors, whose sum is σ = 31481888. Its totient is φ = 31481886.

The previous prime is 31481867. The next prime is 31481899. The reversal of 31481887 is 78818413.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31481887 is a prime.

It is a super-2 number, since 2×31481887² = 1982218418161538, which contains 22 as substring.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31481837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15740943 + 15740944.

It is an arithmetic number, because the mean of its divisors is an integer number (15740944).

Almost surely, 2^31481887 is an apocalyptic number.

31481887 is a deficient number, since it is larger than the sum of its proper divisors (1).

31481887 is an equidigital number, since it uses as much as digits as its factorization.

31481887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43008, while the sum is 40.

The square root of 31481887 is about 5610.8722138363. The cubic root of 31481887 is about 315.7574348261.

The spelling of 31481887 in words is "thirty-one million, four hundred eighty-one thousand, eight hundred eighty-seven".