20887918 has 8 divisors (see below), whose sum is σ = 31384512. Its totient is φ = 10426416.

The previous prime is 20887913. The next prime is 20887921. The reversal of 20887918 is 81978802.

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 (20887913) 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, 7230 + ... + 9697.

It is an arithmetic number, because the mean of its divisors is an integer number (3923064).

Almost surely, 2^20887918 is an apocalyptic number.

20887918 is a deficient number, since it is larger than the sum of its proper divisors (10496594).

20887918 is a wasteful number, since it uses less digits than its factorization.

20887918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17546.

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 20887918 is about 4570.3301850085. The cubic root of 20887918 is about 275.4007072989.

The spelling of 20887918 in words is "twenty million, eight hundred eighty-seven thousand, nine hundred eighteen".