1661250775 has 12 divisors (see below), whose sum is σ = 2060673912. Its totient is φ = 1328534240.

The previous prime is 1661250763. The next prime is 1661250791. The reversal of 1661250775 is 5770521661.

It is a happy number.

It is not a de Polignac number, because 1661250775 - 2⁹ = 1661250263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73077 + ... + 93073.

It is an arithmetic number, because the mean of its divisors is an integer number (171722826).

Almost surely, 2^1661250775 is an apocalyptic number.

1661250775 is a deficient number, since it is larger than the sum of its proper divisors (399423137).

1661250775 is a wasteful number, since it uses less digits than its factorization.

1661250775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23330 (or 23325 counting only the distinct ones).

The product of its (nonzero) digits is 88200, while the sum is 40.

The square root of 1661250775 is about 40758.4442171190. Note that the first 3 decimals coincide. The cubic root of 1661250775 is about 1184.3454579878.

The spelling of 1661250775 in words is "one billion, six hundred sixty-one million, two hundred fifty thousand, seven hundred seventy-five".