166816816501 has 4 divisors (see below), whose sum is σ = 166819919392. Its totient is φ = 166813713612.

The previous prime is 166816816457. The next prime is 166816816519. The reversal of 166816816501 is 105618618661.

It is a happy number.

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 166816816501 - 2¹³ = 166816808309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166816846501) 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, 1469355 + ... + 1578808.

It is an arithmetic number, because the mean of its divisors is an integer number (41704979848).

Almost surely, 2^166816816501 is an apocalyptic number.

It is an amenable number.

166816816501 is a deficient number, since it is larger than the sum of its proper divisors (3102891).

166816816501 is an equidigital number, since it uses as much as digits as its factorization.

166816816501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3102890.

The product of its (nonzero) digits is 414720, while the sum is 49.

The spelling of 166816816501 in words is "one hundred sixty-six billion, eight hundred sixteen million, eight hundred sixteen thousand, five hundred one".