20787986 has 8 divisors (see below), whose sum is σ = 31356720. Its totient is φ = 10335748.

The previous prime is 20787971. The next prime is 20788003. The reversal of 20787986 is 68978702.

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 20787986.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28676 + ... + 29391.

It is an arithmetic number, because the mean of its divisors is an integer number (3919590).

Almost surely, 2^20787986 is an apocalyptic number.

20787986 is a deficient number, since it is larger than the sum of its proper divisors (10568734).

20787986 is a wasteful number, since it uses less digits than its factorization.

20787986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58248.

The product of its (nonzero) digits is 338688, while the sum is 47.

The square root of 20787986 is about 4559.3843882700. The cubic root of 20787986 is about 274.9608142513.

The spelling of 20787986 in words is "twenty million, seven hundred eighty-seven thousand, nine hundred eighty-six".