31440561 has 8 divisors (see below), whose sum is σ = 41947584. Its totient is φ = 20946960.

The previous prime is 31440533. The next prime is 31440571. The reversal of 31440561 is 16504413.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31440561 - 2⁹ = 31440049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31440571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5316 + ... + 9546.

It is an arithmetic number, because the mean of its divisors is an integer number (5243448).

Almost surely, 2^31440561 is an apocalyptic number.

It is an amenable number.

31440561 is a deficient number, since it is larger than the sum of its proper divisors (10507023).

31440561 is a wasteful number, since it uses less digits than its factorization.

31440561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6711.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 31440561 is about 5607.1883328456. The cubic root of 31440561 is about 315.6192103111.

Adding to 31440561 its reverse (16504413), we get a palindrome (47944974).

The spelling of 31440561 in words is "thirty-one million, four hundred forty thousand, five hundred sixty-one".