31242144 has 24 divisors (see below), whose sum is σ = 82010880. Its totient is φ = 10414016.

The previous prime is 31242143. The next prime is 31242149. The reversal of 31242144 is 44124213.

It is a tau number, because it is divible by the number of its divisors (24).

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

It is a self number, because there is not a number n which added to its sum of digits gives 31242144.

It is not an unprimeable number, because it can be changed into a prime (31242143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162624 + ... + 162815.

It is an arithmetic number, because the mean of its divisors is an integer number (3417120).

Almost surely, 2^31242144 is an apocalyptic number.

It is an amenable number.

31242144 is an abundant number, since it is smaller than the sum of its proper divisors (50768736).

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

31242144 is a wasteful number, since it uses less digits than its factorization.

31242144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325452 (or 325444 counting only the distinct ones).

The product of its digits is 768, while the sum is 21.

The square root of 31242144 is about 5589.4672375818. The cubic root of 31242144 is about 314.9538657556.

Adding to 31242144 its reverse (44124213), we get a palindrome (75366357).

The spelling of 31242144 in words is "thirty-one million, two hundred forty-two thousand, one hundred forty-four".