31287396 has 48 divisors (see below), whose sum is σ = 83954304. Its totient is φ = 8883456.

The previous prime is 31287391. The next prime is 31287413. The reversal of 31287396 is 69378213.

It is a super-2 number, since 2×31287396² = 1957802296921632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31287391) 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 15 ways as a sum of consecutive naturals, for example, 13456 + ... + 15608.

It is an arithmetic number, because the mean of its divisors is an integer number (1749048).

Almost surely, 2^31287396 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31287396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41977152).

31287396 is an abundant number, since it is smaller than the sum of its proper divisors (52666908).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31287396 is a wasteful number, since it uses less digits than its factorization.

31287396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2340 (or 2338 counting only the distinct ones).

The product of its digits is 54432, while the sum is 39.

The square root of 31287396 is about 5593.5137436141. The cubic root of 31287396 is about 315.1058550762.

The spelling of 31287396 in words is "thirty-one million, two hundred eighty-seven thousand, three hundred ninety-six".