20631986 has 8 divisors (see below), whose sum is σ = 32576880. Its totient is φ = 9773028.

The previous prime is 20631983. The next prime is 20631991. The reversal of 20631986 is 68913602.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20631983) 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, 271436 + ... + 271511.

It is an arithmetic number, because the mean of its divisors is an integer number (4072110).

Almost surely, 2^20631986 is an apocalyptic number.

20631986 is a deficient number, since it is larger than the sum of its proper divisors (11944894).

20631986 is a wasteful number, since it uses less digits than its factorization.

20631986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542968.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 20631986 is about 4542.2445993143. The cubic root of 20631986 is about 274.2712872444.

The spelling of 20631986 in words is "twenty million, six hundred thirty-one thousand, nine hundred eighty-six".