31440043 has 4 divisors (see below), whose sum is σ = 31651200. Its totient is φ = 31228888.

The previous prime is 31440001. The next prime is 31440049. The reversal of 31440043 is 34004413.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31440043 - 2¹⁷ = 31308971 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31440043.

It is not an unprimeable number, because it can be changed into a prime (31440049) 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, 105355 + ... + 105652.

It is an arithmetic number, because the mean of its divisors is an integer number (7912800).

Almost surely, 2^31440043 is an apocalyptic number.

31440043 is a deficient number, since it is larger than the sum of its proper divisors (211157).

31440043 is a wasteful number, since it uses less digits than its factorization.

31440043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211156.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 31440043 is about 5607.1421419472. The cubic root of 31440043 is about 315.6174769700.

Adding to 31440043 its reverse (34004413), we get a palindrome (65444456).

The spelling of 31440043 in words is "thirty-one million, four hundred forty thousand, forty-three".