166387771 has 4 divisors (see below), whose sum is σ = 181513944. Its totient is φ = 151261600.

The previous prime is 166387751. The next prime is 166387783. The reversal of 166387771 is 177783661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 177783661 = 11 ⋅16162151.

It is a cyclic number.

It is not a de Polignac number, because 166387771 - 2⁷ = 166387643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166387751) 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, 7563070 + ... + 7563091.

It is an arithmetic number, because the mean of its divisors is an integer number (45378486).

Almost surely, 2^166387771 is an apocalyptic number.

166387771 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

166387771 is a deficient number, since it is larger than the sum of its proper divisors (15126173).

166387771 is a wasteful number, since it uses less digits than its factorization.

166387771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15126172.

The product of its digits is 296352, while the sum is 46.

The square root of 166387771 is about 12899.1383820781. The cubic root of 166387771 is about 550.0140723672.

The spelling of 166387771 in words is "one hundred sixty-six million, three hundred eighty-seven thousand, seven hundred seventy-one".