31236138 has 32 divisors (see below), whose sum is σ = 70041600. Its totient is φ = 10317888.

The previous prime is 31236131. The next prime is 31236143. The reversal of 31236138 is 83163213.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (31236131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3543 + ... + 8661.

It is an arithmetic number, because the mean of its divisors is an integer number (2188800).

Almost surely, 2^31236138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31236138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35020800).

31236138 is an abundant number, since it is smaller than the sum of its proper divisors (38805462).

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

31236138 is a wasteful number, since it uses less digits than its factorization.

31236138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5243 (or 5237 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 31236138 is about 5588.9299512518. The cubic root of 31236138 is about 314.9336821840.

It can be divided in two parts, 3123 and 6138, that added together give a cube (9261 = 21³).

The spelling of 31236138 in words is "thirty-one million, two hundred thirty-six thousand, one hundred thirty-eight".