166387639 has 4 divisors (see below), whose sum is σ = 181513800. Its totient is φ = 151261480.

The previous prime is 166387607. The next prime is 166387643. The reversal of 166387639 is 936783661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 166387639 - 2⁵ = 166387607 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166387592 and 166387601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166387439) 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, 7563064 + ... + 7563085.

It is an arithmetic number, because the mean of its divisors is an integer number (45378450).

Almost surely, 2^166387639 is an apocalyptic number.

166387639 is a deficient number, since it is larger than the sum of its proper divisors (15126161).

166387639 is a wasteful number, since it uses less digits than its factorization.

166387639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15126160.

The product of its digits is 979776, while the sum is 49.

The square root of 166387639 is about 12899.1332654562. The cubic root of 166387639 is about 550.0139269201.

The spelling of 166387639 in words is "one hundred sixty-six million, three hundred eighty-seven thousand, six hundred thirty-nine".