16665801 has 4 divisors (see below), whose sum is σ = 22221072. Its totient is φ = 11110532.

The previous prime is 16665769. The next prime is 16665809. The reversal of 16665801 is 10856661.

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 16665801 - 2⁵ = 16665769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16665809) 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, 2777631 + ... + 2777636.

It is an arithmetic number, because the mean of its divisors is an integer number (5555268).

Almost surely, 2^16665801 is an apocalyptic number.

It is an amenable number.

16665801 is a deficient number, since it is larger than the sum of its proper divisors (5555271).

16665801 is an equidigital number, since it uses as much as digits as its factorization.

16665801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5555270.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 16665801 is about 4082.3768811809. The cubic root of 16665801 is about 255.4320549311.

The spelling of 16665801 in words is "sixteen million, six hundred sixty-five thousand, eight hundred one".