31742309 has 4 divisors (see below), whose sum is σ = 31767660. Its totient is φ = 31716960.

The previous prime is 31742257. The next prime is 31742311. The reversal of 31742309 is 90324713.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90324713 = 61 ⋅1480733.

It can be written as a sum of positive squares in 2 ways, for example, as 31024900 + 717409 = 5570^2 + 847^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31742309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31742329) 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, 10694 + ... + 13335.

It is an arithmetic number, because the mean of its divisors is an integer number (7941915).

Almost surely, 2^31742309 is an apocalyptic number.

It is an amenable number.

31742309 is a deficient number, since it is larger than the sum of its proper divisors (25351).

31742309 is a wasteful number, since it uses less digits than its factorization.

31742309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25350.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 31742309 is about 5634.0313275664. The cubic root of 31742309 is about 316.6257063672.

The spelling of 31742309 in words is "thirty-one million, seven hundred forty-two thousand, three hundred nine".