1661774975 has 24 divisors (see below), whose sum is σ = 2403045600. Its totient is φ = 1139496960.

The previous prime is 1661774963. The next prime is 1661774999. The reversal of 1661774975 is 5794771661.

It is not a de Polignac number, because 1661774975 - 2²⁴ = 1644997759 is a prime.

It is a super-2 number, since 2×1661774975² = 5522992135072501250, which contains 22 as substring.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 88322 + ... + 105471.

It is an arithmetic number, because the mean of its divisors is an integer number (100126900).

Almost surely, 2^1661774975 is an apocalyptic number.

1661774975 is a deficient number, since it is larger than the sum of its proper divisors (741270625).

1661774975 is an equidigital number, since it uses as much as digits as its factorization.

1661774975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193824 (or 193805 counting only the distinct ones).

The product of its digits is 2222640, while the sum is 53.

The square root of 1661774975 is about 40764.8742792125. The cubic root of 1661774975 is about 1184.4700164649.

The spelling of 1661774975 in words is "one billion, six hundred sixty-one million, seven hundred seventy-four thousand, nine hundred seventy-five".