20864578 has 8 divisors (see below), whose sum is σ = 35767872. Its totient is φ = 8941956.

The previous prime is 20864573. The next prime is 20864587. The reversal of 20864578 is 87546802.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20864578.

It is not an unprimeable number, because it can be changed into a prime (20864573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 745150 + ... + 745177.

It is an arithmetic number, because the mean of its divisors is an integer number (4470984).

Almost surely, 2^20864578 is an apocalyptic number.

20864578 is a deficient number, since it is larger than the sum of its proper divisors (14903294).

20864578 is a wasteful number, since it uses less digits than its factorization.

20864578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1490336.

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 20864578 is about 4567.7760452982. The cubic root of 20864578 is about 275.2980921868.

The spelling of 20864578 in words is "twenty million, eight hundred sixty-four thousand, five hundred seventy-eight".