165977487971 has 4 divisors (see below), whose sum is σ = 166002300744. Its totient is φ = 165952675200.

The previous prime is 165977487953. The next prime is 165977487979. The reversal of 165977487971 is 179784779561.

165977487971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165977487971 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165977487895 and 165977487904.

It is not an unprimeable number, because it can be changed into a prime (165977487979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12396350 + ... + 12409731.

It is an arithmetic number, because the mean of its divisors is an integer number (41500575186).

Almost surely, 2^165977487971 is an apocalyptic number.

165977487971 is a deficient number, since it is larger than the sum of its proper divisors (24812773).

165977487971 is an equidigital number, since it uses as much as digits as its factorization.

165977487971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24812772.

The product of its digits is 186701760, while the sum is 71.

The spelling of 165977487971 in words is "one hundred sixty-five billion, nine hundred seventy-seven million, four hundred eighty-seven thousand, nine hundred seventy-one".