166813551 has 12 divisors (see below), whose sum is σ = 241064928. Its totient is φ = 111157344.

The previous prime is 166813523. The next prime is 166813583. The reversal of 166813551 is 155318661.

It is not a de Polignac number, because 166813551 - 2⁶ = 166813487 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166813351) 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 11 ways as a sum of consecutive naturals, for example, 35146 + ... + 39608.

It is an arithmetic number, because the mean of its divisors is an integer number (20088744).

Almost surely, 2^166813551 is an apocalyptic number.

166813551 is a deficient number, since it is larger than the sum of its proper divisors (74251377).

166813551 is a wasteful number, since it uses less digits than its factorization.

166813551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8622 (or 8619 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 166813551 is about 12915.6320402836. The cubic root of 166813551 is about 550.4828278072.

The spelling of 166813551 in words is "one hundred sixty-six million, eight hundred thirteen thousand, five hundred fifty-one".