31320081 has 16 divisors (see below), whose sum is σ = 49969920. Its totient is φ = 19273680.

The previous prime is 31320073. The next prime is 31320083. The reversal of 31320081 is 18002313.

It is not a de Polignac number, because 31320081 - 2³ = 31320073 is a prime.

It is a super-2 number, since 2×31320081² = 1961894947693122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31320083) 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 in 15 ways as a sum of consecutive naturals, for example, 44265 + ... + 44966.

It is an arithmetic number, because the mean of its divisors is an integer number (3123120).

Almost surely, 2^31320081 is an apocalyptic number.

It is an amenable number.

31320081 is a deficient number, since it is larger than the sum of its proper divisors (18649839).

31320081 is a wasteful number, since it uses less digits than its factorization.

31320081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89253 (or 89247 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 31320081 is about 5596.4346686082. The cubic root of 31320081 is about 315.2155440866.

Adding to 31320081 its reverse (18002313), we get a palindrome (49322394).

The spelling of 31320081 in words is "thirty-one million, three hundred twenty thousand, eighty-one".