20705778 has 24 divisors (see below), whose sum is σ = 45064188. Its totient is φ = 6870912.

The previous prime is 20705777. The next prime is 20705791. The reversal of 20705778 is 87750702.

It can be written as a sum of positive squares in 2 ways, for example, as 19954089 + 751689 = 4467^2 + 867^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20705777) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1726 + ... + 6662.

Almost surely, 2^20705778 is an apocalyptic number.

20705778 is an abundant number, since it is smaller than the sum of its proper divisors (24358410).

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

20705778 is a wasteful number, since it uses less digits than its factorization.

20705778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5178 (or 5175 counting only the distinct ones).

The product of its (nonzero) digits is 27440, while the sum is 36.

The square root of 20705778 is about 4550.3602055222. The cubic root of 20705778 is about 274.5978828165.

The spelling of 20705778 in words is "twenty million, seven hundred five thousand, seven hundred seventy-eight".