166011551 has 4 divisors (see below), whose sum is σ = 166706400. Its totient is φ = 165316704.

The previous prime is 166011533. The next prime is 166011553. The reversal of 166011551 is 155110661.

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-166011551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166011551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166011553) 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, 347066 + ... + 347543.

It is an arithmetic number, because the mean of its divisors is an integer number (41676600).

Almost surely, 2^166011551 is an apocalyptic number.

166011551 is a deficient number, since it is larger than the sum of its proper divisors (694849).

166011551 is an equidigital number, since it uses as much as digits as its factorization.

166011551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694848.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 166011551 is about 12884.5469846634. The cubic root of 166011551 is about 549.5992132505.

The spelling of 166011551 in words is "one hundred sixty-six million, eleven thousand, five hundred fifty-one".