31447661 has 6 divisors (see below), whose sum is σ = 36582030. Its totient is φ = 26955096.

The previous prime is 31447657. The next prime is 31447667. The reversal of 31447661 is 16674413.

It can be written as a sum of positive squares in only one way, i.e., 30580900 + 866761 = 5530^2 + 931^2 .

It is not a de Polignac number, because 31447661 - 2² = 31447657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31447667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 320846 + ... + 320943.

It is an arithmetic number, because the mean of its divisors is an integer number (6097005).

Almost surely, 2^31447661 is an apocalyptic number.

It is an amenable number.

31447661 is a deficient number, since it is larger than the sum of its proper divisors (5134369).

31447661 is an equidigital number, since it uses as much as digits as its factorization.

31447661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641803 (or 641796 counting only the distinct ones).

The product of its digits is 12096, while the sum is 32.

The square root of 31447661 is about 5607.8214129910. The cubic root of 31447661 is about 315.6429665425.

The spelling of 31447661 in words is "thirty-one million, four hundred forty-seven thousand, six hundred sixty-one".