66671810 has 8 divisors (see below), whose sum is σ = 120009276. Its totient is φ = 26668720.

The previous prime is 66671809. The next prime is 66671831. The reversal of 66671810 is 1817666.

It can be written as a sum of positive squares in 2 ways, for example, as 66210769 + 461041 = 8137^2 + 679^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×66671810² = 8890260497352200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3333581 + ... + 3333600.

Almost surely, 2^66671810 is an apocalyptic number.

66671810 is a deficient number, since it is larger than the sum of its proper divisors (53337466).

66671810 is a wasteful number, since it uses less digits than its factorization.

66671810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6667188.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 66671810 is about 8165.2807667587. The cubic root of 66671810 is about 405.4905603675.

The spelling of 66671810 in words is "sixty-six million, six hundred seventy-one thousand, eight hundred ten".