161251225 has 6 divisors (see below), whose sum is σ = 199951550. Its totient is φ = 129000960.

The previous prime is 161251169. The next prime is 161251241. The reversal of 161251225 is 522152161.

It can be written as a sum of positive squares in 3 ways, for example, as 9665881 + 151585344 = 3109^2 + 12312^2 .

It is not a de Polignac number, because 161251225 - 2¹⁷ = 161120153 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: 6450049 = 161251225 / (1 + 6 + 1 + 2 + 5 + 1 + 2 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 161251225.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3225000 + ... + 3225049.

Almost surely, 2^161251225 is an apocalyptic number.

It is an amenable number.

161251225 is a deficient number, since it is larger than the sum of its proper divisors (38700325).

161251225 is an equidigital number, since it uses as much as digits as its factorization.

161251225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6450059 (or 6450054 counting only the distinct ones).

The product of its digits is 1200, while the sum is 25.

The square root of 161251225 is about 12698.4733334366. The cubic root of 161251225 is about 544.2949950376.

The spelling of 161251225 in words is "one hundred sixty-one million, two hundred fifty-one thousand, two hundred twenty-five".