31442240 has 28 divisors (see below), whose sum is σ = 74872596. Its totient is φ = 12576768.

The previous prime is 31442239. The next prime is 31442261. The reversal of 31442240 is 4224413.

It can be written as a sum of positive squares in 2 ways, for example, as 8248384 + 23193856 = 2872^2 + 4816^2 .

It is a super-2 number, since 2×31442240² = 1977228912435200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 48809 + ... + 49448.

Almost surely, 2^31442240 is an apocalyptic number.

It is an amenable number.

31442240 is an abundant number, since it is smaller than the sum of its proper divisors (43430356).

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

31442240 is an equidigital number, since it uses as much as digits as its factorization.

31442240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98274 (or 98264 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 31442240 is about 5607.3380493778. The cubic root of 31442240 is about 315.6248284808.

Adding to 31442240 its reverse (4224413), we get a palindrome (35666653).

The spelling of 31442240 in words is "thirty-one million, four hundred forty-two thousand, two hundred forty".