20387986 has 8 divisors (see below), whose sum is σ = 31636620. Its totient is φ = 9842448.

The previous prime is 20387953. The next prime is 20387993. The reversal of 20387986 is 68978302.

It can be written as a sum of positive squares in 2 ways, for example, as 19971961 + 416025 = 4469^2 + 645^2 .

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

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 in 3 ways as a sum of consecutive naturals, for example, 175701 + ... + 175816.

Almost surely, 2^20387986 is an apocalyptic number.

20387986 is a deficient number, since it is larger than the sum of its proper divisors (11248634).

20387986 is a wasteful number, since it uses less digits than its factorization.

20387986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351548.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 20387986 is about 4515.3057482301. The cubic root of 20387986 is about 273.1857922095.

The spelling of 20387986 in words is "twenty million, three hundred eighty-seven thousand, nine hundred eighty-six".