20197986 has 16 divisors (see below), whose sum is σ = 40440384. Its totient is φ = 6725264.

The previous prime is 20197981. The next prime is 20197987. The reversal of 20197986 is 68979102.

It is not an unprimeable number, because it can be changed into a prime (20197981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8635 + ... + 10721.

It is an arithmetic number, because the mean of its divisors is an integer number (2527524).

Almost surely, 2^20197986 is an apocalyptic number.

20197986 is an abundant number, since it is smaller than the sum of its proper divisors (20242398).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20197986 is a wasteful number, since it uses less digits than its factorization.

20197986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3705.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 20197986 is about 4494.2169507045. The cubic root of 20197986 is about 272.3345167018.

The spelling of 20197986 in words is "twenty million, one hundred ninety-seven thousand, nine hundred eighty-six".