20775666 has 32 divisors (see below), whose sum is σ = 44323200. Its totient is φ = 6469376.

The previous prime is 20775661. The next prime is 20775697. The reversal of 20775666 is 66657702.

It is not an unprimeable number, because it can be changed into a prime (20775661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14515 + ... + 15881.

It is an arithmetic number, because the mean of its divisors is an integer number (1385100).

Almost surely, 2^20775666 is an apocalyptic number.

20775666 is an abundant number, since it is smaller than the sum of its proper divisors (23547534).

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

20775666 is a wasteful number, since it uses less digits than its factorization.

20775666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1538.

The product of its (nonzero) digits is 105840, while the sum is 39.

The square root of 20775666 is about 4558.0331284448. The cubic root of 20775666 is about 274.9064850078.

The spelling of 20775666 in words is "twenty million, seven hundred seventy-five thousand, six hundred sixty-six".