31961137 has 4 divisors (see below), whose sum is σ = 34419700. Its totient is φ = 29502576.

The previous prime is 31961131. The next prime is 31961143. The reversal of 31961137 is 73116913.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73116913 = 47 ⋅1555679.

It is an interprime number because it is at equal distance from previous prime (31961131) and next prime (31961143).

It can be written as a sum of positive squares in 2 ways, for example, as 15241216 + 16719921 = 3904^2 + 4089^2 .

It is a cyclic number.

It is not a de Polignac number, because 31961137 - 2⁷ = 31961009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31961099 and 31961108.

It is not an unprimeable number, because it can be changed into a prime (31961131) 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, 1229262 + ... + 1229287.

It is an arithmetic number, because the mean of its divisors is an integer number (8604925).

Almost surely, 2^31961137 is an apocalyptic number.

It is an amenable number.

31961137 is a deficient number, since it is larger than the sum of its proper divisors (2458563).

31961137 is a wasteful number, since it uses less digits than its factorization.

31961137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2458562.

The product of its digits is 3402, while the sum is 31.

The square root of 31961137 is about 5653.4181695679. The cubic root of 31961137 is about 317.3516350646.

The spelling of 31961137 in words is "thirty-one million, nine hundred sixty-one thousand, one hundred thirty-seven".