31287742 has 16 divisors (see below), whose sum is σ = 48742272. Its totient is φ = 15046560.

The previous prime is 31287731. The next prime is 31287743. The reversal of 31287742 is 24778213.

It is a junction number, because it is equal to n+sod(n) for n = 31287698 and 31287707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31287743) 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, 9268 + ... + 12184.

It is an arithmetic number, because the mean of its divisors is an integer number (3046392).

Almost surely, 2^31287742 is an apocalyptic number.

31287742 is a deficient number, since it is larger than the sum of its proper divisors (17454530).

31287742 is a wasteful number, since it uses less digits than its factorization.

31287742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3123.

The product of its digits is 18816, while the sum is 34.

The square root of 31287742 is about 5593.5446722092. The cubic root of 31287742 is about 315.1070166326.

The spelling of 31287742 in words is "thirty-one million, two hundred eighty-seven thousand, seven hundred forty-two".