166138810 has 16 divisors (see below), whose sum is σ = 299415816. Its totient is φ = 66374208.

The previous prime is 166138789. The next prime is 166138823. The reversal of 166138810 is 18831661.

It can be written as a sum of positive squares in 4 ways, for example, as 109181601 + 56957209 = 10449^2 + 7547^2 .

It is a super-2 number, since 2×166138810² = 55204208376432200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1209 + ... + 18268.

Almost surely, 2^166138810 is an apocalyptic number.

166138810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

166138810 is a deficient number, since it is larger than the sum of its proper divisors (133277006).

166138810 is a wasteful number, since it uses less digits than its factorization.

166138810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20337.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 166138810 is about 12889.4844737871. The cubic root of 166138810 is about 549.7396122807.

The spelling of 166138810 in words is "one hundred sixty-six million, one hundred thirty-eight thousand, eight hundred ten".