16668778 has 16 divisors (see below), whose sum is σ = 29240640. Its totient is φ = 6977376.

The previous prime is 16668749. The next prime is 16668791. The reversal of 16668778 is 87786661.

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, 13243 + ... + 14446.

It is an arithmetic number, because the mean of its divisors is an integer number (1827540).

Almost surely, 2^16668778 is an apocalyptic number.

16668778 is a deficient number, since it is larger than the sum of its proper divisors (12571862).

16668778 is a wasteful number, since it uses less digits than its factorization.

16668778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27741.

The product of its digits is 677376, while the sum is 49.

The square root of 16668778 is about 4082.7414809170. The cubic root of 16668778 is about 255.4472632401.

The spelling of 16668778 in words is "sixteen million, six hundred sixty-eight thousand, seven hundred seventy-eight".