161431225 has 6 divisors (see below), whose sum is σ = 200174750. Its totient is φ = 129144960.

The previous prime is 161431217. The next prime is 161431243. The reversal of 161431225 is 522134161.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 45373696 + 116057529 = 6736^2 + 10773^2 .

It is not a de Polignac number, because 161431225 - 2³ = 161431217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 6457249 = 161431225 / (1 + 6 + 1 + 4 + 3 + 1 + 2 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 161431225.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3228600 + ... + 3228649.

Almost surely, 2^161431225 is an apocalyptic number.

It is an amenable number.

161431225 is a deficient number, since it is larger than the sum of its proper divisors (38743525).

161431225 is an equidigital number, since it uses as much as digits as its factorization.

161431225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6457259 (or 6457254 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 161431225 is about 12705.5588228145. The cubic root of 161431225 is about 544.4974465577.

Adding to 161431225 its reverse (522134161), we get a palindrome (683565386).

The spelling of 161431225 in words is "one hundred sixty-one million, four hundred thirty-one thousand, two hundred twenty-five".