20983986 has 12 divisors (see below), whose sum is σ = 45465342. Its totient is φ = 6994656.

The previous prime is 20983969. The next prime is 20983997. The reversal of 20983986 is 68938902.

It can be written as a sum of positive squares in only one way, i.e., 20930625 + 53361 = 4575^2 + 231^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 582871 + ... + 582906.

Almost surely, 2^20983986 is an apocalyptic number.

20983986 is an abundant number, since it is smaller than the sum of its proper divisors (24481356).

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

20983986 is a wasteful number, since it uses less digits than its factorization.

20983986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1165785 (or 1165782 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 20983986 is about 4580.8280910770. The cubic root of 20983986 is about 275.8222705794.

It can be divided in two parts, 2098 and 3986, that added together give a square (6084 = 78²).

The spelling of 20983986 in words is "twenty million, nine hundred eighty-three thousand, nine hundred eighty-six".