20566478 has 4 divisors (see below), whose sum is σ = 30849720. Its totient is φ = 10283238.

The previous prime is 20566453. The next prime is 20566489. The reversal of 20566478 is 87466502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5141618 + ... + 5141621.

It is an arithmetic number, because the mean of its divisors is an integer number (7712430).

Almost surely, 2^20566478 is an apocalyptic number.

20566478 is a deficient number, since it is larger than the sum of its proper divisors (10283242).

20566478 is a wasteful number, since it uses less digits than its factorization.

20566478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10283241.

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 20566478 is about 4535.0278940708. The cubic root of 20566478 is about 273.9807026387.

The spelling of 20566478 in words is "twenty million, five hundred sixty-six thousand, four hundred seventy-eight".