31422240 has 72 divisors (see below), whose sum is σ = 107233308. Its totient is φ = 8378880.

The previous prime is 31422233. The next prime is 31422241. The reversal of 31422240 is 4222413.

31422240 is a `hidden beast` number, since 3 + 1 + 422 + 240 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 31404816 + 17424 = 5604^2 + 132^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (31422241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9471 + ... + 12350.

Almost surely, 2^31422240 is an apocalyptic number.

31422240 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31422240 is an abundant number, since it is smaller than the sum of its proper divisors (75811068).

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

31422240 is a wasteful number, since it uses less digits than its factorization.

31422240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21842 (or 21831 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 31422240 is about 5605.5543882831. The cubic root of 31422240 is about 315.5578926701.

Adding to 31422240 its reverse (4222413), we get a palindrome (35644653).

The spelling of 31422240 in words is "thirty-one million, four hundred twenty-two thousand, two hundred forty".