166555631 has 8 divisors (see below), whose sum is σ = 181958400. Its totient is φ = 151196440.

The previous prime is 166555607. The next prime is 166555633. The reversal of 166555631 is 136555661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166555631 - 2¹⁰ = 166554607 is a prime.

It is a super-2 number, since 2×166555631² = 55481556435616322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166555633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2621 + ... + 18438.

It is an arithmetic number, because the mean of its divisors is an integer number (22744800).

Almost surely, 2^166555631 is an apocalyptic number.

166555631 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

166555631 is a deficient number, since it is larger than the sum of its proper divisors (15402769).

166555631 is a wasteful number, since it uses less digits than its factorization.

166555631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21789.

The product of its digits is 81000, while the sum is 38.

The square root of 166555631 is about 12905.6433779955. The cubic root of 166555631 is about 550.1989704351.

The spelling of 166555631 in words is "one hundred sixty-six million, five hundred fifty-five thousand, six hundred thirty-one".