1661050025 has 24 divisors (see below), whose sum is σ = 2191315104. Its totient is φ = 1244678400.

The previous prime is 1661050021. The next prime is 1661050031. The reversal of 1661050025 is 5200501661.

It is not a de Polignac number, because 1661050025 - 2² = 1661050021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1661049976 and 1661050003.

It is not an unprimeable number, because it can be changed into a prime (1661050021) 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 23 ways as a sum of consecutive naturals, for example, 80414 + ... + 98936.

It is an arithmetic number, because the mean of its divisors is an integer number (91304796).

Almost surely, 2^1661050025 is an apocalyptic number.

It is an amenable number.

1661050025 is a deficient number, since it is larger than the sum of its proper divisors (530265079).

1661050025 is a wasteful number, since it uses less digits than its factorization.

1661050025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18761 (or 18756 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 1661050025 is about 40755.9814628479. The cubic root of 1661050025 is about 1184.2977495719.

Adding to 1661050025 its reverse (5200501661), we get a palindrome (6861551686).

The spelling of 1661050025 in words is "one billion, six hundred sixty-one million, fifty thousand, twenty-five".