20980786 has 4 divisors (see below), whose sum is σ = 31471182. Its totient is φ = 10490392.

The previous prime is 20980783. The next prime is 20980787. The reversal of 20980786 is 68708902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20657025 + 323761 = 4545^2 + 569^2 .

It is not an unprimeable number, because it can be changed into a prime (20980783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5245195 + ... + 5245198.

Almost surely, 2^20980786 is an apocalyptic number.

20980786 is a deficient number, since it is larger than the sum of its proper divisors (10490396).

20980786 is a wasteful number, since it uses less digits than its factorization.

20980786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10490395.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 20980786 is about 4580.4787959339. The cubic root of 20980786 is about 275.8082491547.

The spelling of 20980786 in words is "twenty million, nine hundred eighty thousand, seven hundred eighty-six".