20066778 has 40 divisors (see below), whose sum is σ = 45463572. Its totient is φ = 6614784.

The previous prime is 20066777. The next prime is 20066797. The reversal of 20066778 is 87766002.

It can be written as a sum of positive squares in 2 ways, for example, as 20007729 + 59049 = 4473^2 + 243^2 .

It is not an unprimeable number, because it can be changed into a prime (20066771) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15076 + ... + 16352.

Almost surely, 2^20066778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20066778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22731786).

20066778 is an abundant number, since it is smaller than the sum of its proper divisors (25396794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20066778 is a wasteful number, since it uses less digits than its factorization.

20066778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388 (or 1379 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 20066778 is about 4479.5957406891. The cubic root of 20066778 is about 271.7435316810.

The spelling of 20066778 in words is "twenty million, sixty-six thousand, seven hundred seventy-eight".