31081994 has 4 divisors (see below), whose sum is σ = 46622994. Its totient is φ = 15540996.

The previous prime is 31081987. The next prime is 31082017. The reversal of 31081994 is 49918013.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49918013 = 719 ⋅69427.

It can be written as a sum of positive squares in only one way, i.e., 31080625 + 1369 = 5575^2 + 37^2 .

It is a Curzon number.

It is an unprimeable number.

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, 7770497 + ... + 7770500.

Almost surely, 2^31081994 is an apocalyptic number.

31081994 is a deficient number, since it is larger than the sum of its proper divisors (15541000).

31081994 is a wasteful number, since it uses less digits than its factorization.

31081994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15540999.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 31081994 is about 5575.1227789171. The cubic root of 31081994 is about 314.4147830954.

The spelling of 31081994 in words is "thirty-one million, eighty-one thousand, nine hundred ninety-four".