31138224 has 80 divisors (see below), whose sum is σ = 87494400. Its totient is φ = 9485568.

The previous prime is 31138213. The next prime is 31138249. The reversal of 31138224 is 42283113.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 31138194 and 31138203.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86557 + ... + 86915.

It is an arithmetic number, because the mean of its divisors is an integer number (1093680).

Almost surely, 2^31138224 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 31138224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43747200).

31138224 is an abundant number, since it is smaller than the sum of its proper divisors (56356176).

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

31138224 is a wasteful number, since it uses less digits than its factorization.

31138224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522 (or 516 counting only the distinct ones).

The product of its digits is 1152, while the sum is 24.

The square root of 31138224 is about 5580.1634384667. The cubic root of 31138224 is about 314.6042700021.

The spelling of 31138224 in words is "thirty-one million, one hundred thirty-eight thousand, two hundred twenty-four".