31472561 has 4 divisors (see below), whose sum is σ = 31484772. Its totient is φ = 31460352.

The previous prime is 31472537. The next prime is 31472587. The reversal of 31472561 is 16527413.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 18113536 + 13359025 = 4256^2 + 3655^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31472561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31472501) by changing a digit.

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, 560 + ... + 7953.

It is an arithmetic number, because the mean of its divisors is an integer number (7871193).

Almost surely, 2^31472561 is an apocalyptic number.

It is an amenable number.

31472561 is a deficient number, since it is larger than the sum of its proper divisors (12211).

31472561 is an equidigital number, since it uses as much as digits as its factorization.

31472561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12210.

The product of its digits is 5040, while the sum is 29.

The square root of 31472561 is about 5610.0410871936. The cubic root of 31472561 is about 315.7262524019.

Adding to 31472561 its reverse (16527413), we get a palindrome (47999974).

The spelling of 31472561 in words is "thirty-one million, four hundred seventy-two thousand, five hundred sixty-one".