165866973 has 4 divisors (see below), whose sum is σ = 221155968. Its totient is φ = 110577980.

The previous prime is 165866971. The next prime is 165866989. The reversal of 165866973 is 379668561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165866973 - 2¹ = 165866971 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165866971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27644493 + ... + 27644498.

It is an arithmetic number, because the mean of its divisors is an integer number (55288992).

Almost surely, 2^165866973 is an apocalyptic number.

It is an amenable number.

165866973 is a deficient number, since it is larger than the sum of its proper divisors (55288995).

165866973 is an equidigital number, since it uses as much as digits as its factorization.

165866973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55288994.

The product of its digits is 1632960, while the sum is 51.

The square root of 165866973 is about 12878.9352432567. The cubic root of 165866973 is about 549.4396198714.

The spelling of 165866973 in words is "one hundred sixty-five million, eight hundred sixty-six thousand, nine hundred seventy-three".