166555623 has 16 divisors (see below), whose sum is σ = 240196320. Its totient is φ = 102050304.

The previous prime is 166555607. The next prime is 166555633. The reversal of 166555623 is 326555661.

It is not a de Polignac number, because 166555623 - 2⁴ = 166555607 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

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 15 ways as a sum of consecutive naturals, for example, 78 + ... + 18251.

It is an arithmetic number, because the mean of its divisors is an integer number (15012270).

Almost surely, 2^166555623 is an apocalyptic number.

166555623 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

166555623 is a deficient number, since it is larger than the sum of its proper divisors (73640697).

166555623 is a wasteful number, since it uses less digits than its factorization.

166555623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18578.

The product of its digits is 162000, while the sum is 39.

The square root of 166555623 is about 12905.6430680536. The cubic root of 166555623 is about 550.1989616261.

The spelling of 166555623 in words is "one hundred sixty-six million, five hundred fifty-five thousand, six hundred twenty-three".