166642587 has 12 divisors (see below), whose sum is σ = 246304344. Its totient is φ = 108511200.

The previous prime is 166642571. The next prime is 166642591. The reversal of 166642587 is 785246661.

It is not a de Polignac number, because 166642587 - 2⁴ = 166642571 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166644587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 214914 + ... + 215687.

It is an arithmetic number, because the mean of its divisors is an integer number (20525362).

Almost surely, 2^166642587 is an apocalyptic number.

166642587 is a deficient number, since it is larger than the sum of its proper divisors (79661757).

166642587 is a wasteful number, since it uses less digits than its factorization.

166642587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430650 (or 430647 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 166642587 is about 12909.0118521907. The cubic root of 166642587 is about 550.2947037701.

It can be divided in two parts, 1666 and 42587, that added together give a triangular number (44253 = T₂₉₇).

The spelling of 166642587 in words is "one hundred sixty-six million, six hundred forty-two thousand, five hundred eighty-seven".