31204081 has 4 divisors (see below), whose sum is σ = 31216752. Its totient is φ = 31191412.

The previous prime is 31204067. The next prime is 31204091. The reversal of 31204081 is 18040213.

It is the 2281-st star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18040213 = 17 ⋅1061189.

It is a cyclic number.

It is not a de Polignac number, because 31204081 - 2⁹ = 31203569 is a prime.

It is a super-2 number, since 2×31204081² = 1947389342109122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31204021) 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 3 ways as a sum of consecutive naturals, for example, 1315 + ... + 8008.

It is an arithmetic number, because the mean of its divisors is an integer number (7804188).

Almost surely, 2^31204081 is an apocalyptic number.

It is an amenable number.

31204081 is a deficient number, since it is larger than the sum of its proper divisors (12671).

31204081 is an equidigital number, since it uses as much as digits as its factorization.

31204081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12670.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 31204081 is about 5586.0613136628. The cubic root of 31204081 is about 314.8259086736.

Adding to 31204081 its reverse (18040213), we get a palindrome (49244294).

The spelling of 31204081 in words is "thirty-one million, two hundred four thousand, eighty-one".