1661141225 has 6 divisors (see below), whose sum is σ = 2059815150. Its totient is φ = 1328912960.

The previous prime is 1661141221. The next prime is 1661141239. The reversal of 1661141225 is 5221411661.

It can be written as a sum of positive squares in 3 ways, for example, as 11075584 + 1650065641 = 3328^2 + 40621^2 .

It is not a de Polignac number, because 1661141225 - 2² = 1661141221 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661141221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33222800 + ... + 33222849.

It is an arithmetic number, because the mean of its divisors is an integer number (343302525).

Almost surely, 2^1661141225 is an apocalyptic number.

It is an amenable number.

1661141225 is a deficient number, since it is larger than the sum of its proper divisors (398673925).

1661141225 is an equidigital number, since it uses as much as digits as its factorization.

1661141225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66445659 (or 66445654 counting only the distinct ones).

The product of its digits is 2880, while the sum is 29.

The square root of 1661141225 is about 40757.1003016652. The cubic root of 1661141225 is about 1184.3194238094.

Adding to 1661141225 its reverse (5221411661), we get a palindrome (6882552886).

The spelling of 1661141225 in words is "one billion, six hundred sixty-one million, one hundred forty-one thousand, two hundred twenty-five".