31550161 has 4 divisors (see below), whose sum is σ = 31625524. Its totient is φ = 31474800.

The previous prime is 31550153. The next prime is 31550177. The reversal of 31550161 is 16105513.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1782225 + 29767936 = 1335^2 + 5456^2 .

It is a cyclic number.

It is not a de Polignac number, because 31550161 - 2³ = 31550153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31550111) 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, 37050 + ... + 37891.

It is an arithmetic number, because the mean of its divisors is an integer number (7906381).

Almost surely, 2^31550161 is an apocalyptic number.

It is an amenable number.

31550161 is a deficient number, since it is larger than the sum of its proper divisors (75363).

31550161 is an equidigital number, since it uses as much as digits as its factorization.

31550161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75362.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 31550161 is about 5616.9529996253. The cubic root of 31550161 is about 315.9855284993.

Adding to 31550161 its reverse (16105513), we get a palindrome (47655674).

The spelling of 31550161 in words is "thirty-one million, five hundred fifty thousand, one hundred sixty-one".