31463561 has 4 divisors (see below), whose sum is σ = 31476372. Its totient is φ = 31450752.

The previous prime is 31463533. The next prime is 31463587. The reversal of 31463561 is 16536413.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16536413 = 139 ⋅118967.

It can be written as a sum of positive squares in 2 ways, for example, as 14776336 + 16687225 = 3844^2 + 4085^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31463561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31463591) 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, 1436 + ... + 8061.

It is an arithmetic number, because the mean of its divisors is an integer number (7869093).

Almost surely, 2^31463561 is an apocalyptic number.

It is an amenable number.

31463561 is a deficient number, since it is larger than the sum of its proper divisors (12811).

31463561 is an equidigital number, since it uses as much as digits as its factorization.

31463561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12810.

The product of its digits is 6480, while the sum is 29.

The square root of 31463561 is about 5609.2388966775. The cubic root of 31463561 is about 315.6961541503.

Adding to 31463561 its reverse (16536413), we get a palindrome (47999974).

The spelling of 31463561 in words is "thirty-one million, four hundred sixty-three thousand, five hundred sixty-one".