66777890 has 8 divisors (see below), whose sum is σ = 120200220. Its totient is φ = 26711152.

The previous prime is 66777881. The next prime is 66777917. The reversal of 66777890 is 9877766.

It can be written as a sum of positive squares in 2 ways, for example, as 64176121 + 2601769 = 8011^2 + 1613^2 .

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

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, 3338885 + ... + 3338904.

Almost surely, 2^66777890 is an apocalyptic number.

66777890 is a deficient number, since it is larger than the sum of its proper divisors (53422330).

66777890 is a wasteful number, since it uses less digits than its factorization.

66777890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6677796.

The product of its (nonzero) digits is 889056, while the sum is 50.

The square root of 66777890 is about 8171.7739812112. The cubic root of 66777890 is about 405.7055020132.

The spelling of 66777890 in words is "sixty-six million, seven hundred seventy-seven thousand, eight hundred ninety".