20641678 has 8 divisors (see below), whose sum is σ = 32030280. Its totient is φ = 9964920.

The previous prime is 20641669. The next prime is 20641679. The reversal of 20641678 is 87614602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20641679) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177888 + ... + 178003.

It is an arithmetic number, because the mean of its divisors is an integer number (4003785).

Almost surely, 2^20641678 is an apocalyptic number.

20641678 is a deficient number, since it is larger than the sum of its proper divisors (11388602).

20641678 is a wasteful number, since it uses less digits than its factorization.

20641678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355922.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 20641678 is about 4543.3113474645. The cubic root of 20641678 is about 274.3142273858.

The spelling of 20641678 in words is "twenty million, six hundred forty-one thousand, six hundred seventy-eight".