31481819 has 2 divisors, whose sum is σ = 31481820. Its totient is φ = 31481818.

The previous prime is 31481767. The next prime is 31481831. The reversal of 31481819 is 91818413.

It is a strong prime.

It is an emirp because it is prime and its reverse (91818413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31481819 - 2¹² = 31477723 is a prime.

It is a super-2 number, since 2×31481819² = 1982209855097522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is equal to p_1943783 and since 31481819 and 1943783 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (31481899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15740909 + 15740910.

It is an arithmetic number, because the mean of its divisors is an integer number (15740910).

Almost surely, 2^31481819 is an apocalyptic number.

31481819 is a deficient number, since it is larger than the sum of its proper divisors (1).

31481819 is an equidigital number, since it uses as much as digits as its factorization.

31481819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 35.

The square root of 31481819 is about 5610.8661541691. The cubic root of 31481819 is about 315.7572074835.

The spelling of 31481819 in words is "thirty-one million, four hundred eighty-one thousand, eight hundred nineteen".