20858918 has 4 divisors (see below), whose sum is σ = 31288380. Its totient is φ = 10429458.

The previous prime is 20858899. The next prime is 20858927. The reversal of 20858918 is 81985802.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5214728 + ... + 5214731.

It is an arithmetic number, because the mean of its divisors is an integer number (7822095).

Almost surely, 2^20858918 is an apocalyptic number.

20858918 is a deficient number, since it is larger than the sum of its proper divisors (10429462).

20858918 is a wasteful number, since it uses less digits than its factorization.

20858918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10429461.

The product of its (nonzero) digits is 46080, while the sum is 41.

The square root of 20858918 is about 4567.1564457548. The cubic root of 20858918 is about 275.2731962743.

The spelling of 20858918 in words is "twenty million, eight hundred fifty-eight thousand, nine hundred eighteen".