31477681 has 4 divisors (see below), whose sum is σ = 31597632. Its totient is φ = 31357732.

The previous prime is 31477669. The next prime is 31477697. The reversal of 31477681 is 18677413.

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.

It is a cyclic number.

It is not a de Polignac number, because 31477681 - 2⁷ = 31477553 is a prime.

It is a super-2 number, since 2×31477681² = 1981688802275522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31477681.

It is not an unprimeable number, because it can be changed into a prime (31477181) 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, 59581 + ... + 60106.

It is an arithmetic number, because the mean of its divisors is an integer number (7899408).

Almost surely, 2^31477681 is an apocalyptic number.

It is an amenable number.

31477681 is a deficient number, since it is larger than the sum of its proper divisors (119951).

31477681 is a wasteful number, since it uses less digits than its factorization.

31477681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119950.

The product of its digits is 28224, while the sum is 37.

The square root of 31477681 is about 5610.4973932799. The cubic root of 31477681 is about 315.7433724022.

The spelling of 31477681 in words is "thirty-one million, four hundred seventy-seven thousand, six hundred eighty-one".