31361981 has 8 divisors (see below), whose sum is σ = 36450240. Its totient is φ = 26425728.

The previous prime is 31361971. The next prime is 31362011. The reversal of 31361981 is 18916313.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31361981 - 2⁶ = 31361917 is a prime.

It is a super-2 number, since 2×31361981² = 1967147704488722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31361971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37556 + ... + 38381.

It is an arithmetic number, because the mean of its divisors is an integer number (4556280).

Almost surely, 2^31361981 is an apocalyptic number.

It is an amenable number.

31361981 is a deficient number, since it is larger than the sum of its proper divisors (5088259).

31361981 is an equidigital number, since it uses as much as digits as its factorization.

31361981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76003.

The product of its digits is 3888, while the sum is 32.

The square root of 31361981 is about 5600.1768722068. The cubic root of 31361981 is about 315.3560465542.

The spelling of 31361981 in words is "thirty-one million, three hundred sixty-one thousand, nine hundred eighty-one".