1665971995 has 16 divisors (see below), whose sum is σ = 2104564032. Its totient is φ = 1263539200.

The previous prime is 1665971971. The next prime is 1665971999. The reversal of 1665971995 is 5991795661.

It is not a de Polignac number, because 1665971995 - 2¹⁵ = 1665939227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1665971999) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 51106 + ... + 77095.

It is an arithmetic number, because the mean of its divisors is an integer number (131535252).

Almost surely, 2^1665971995 is an apocalyptic number.

1665971995 is a deficient number, since it is larger than the sum of its proper divisors (438592037).

1665971995 is a wasteful number, since it uses less digits than its factorization.

1665971995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128342.

The product of its digits is 4592700, while the sum is 58.

The square root of 1665971995 is about 40816.3202040556. The cubic root of 1665971995 is about 1185.4663537388.

The spelling of 1665971995 in words is "one billion, six hundred sixty-five million, nine hundred seventy-one thousand, nine hundred ninety-five".