20678890 has 16 divisors (see below), whose sum is σ = 37276200. Its totient is φ = 8259520.

The previous prime is 20678873. The next prime is 20678899. The reversal of 20678890 is 9887602.

It can be written as a sum of positive squares in 4 ways, for example, as 19704721 + 974169 = 4439^2 + 987^2 .

It is not an unprimeable number, because it can be changed into a prime (20678899) 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 7 ways as a sum of consecutive naturals, for example, 9636 + ... + 11584.

Almost surely, 2^20678890 is an apocalyptic number.

20678890 is a deficient number, since it is larger than the sum of its proper divisors (16597310).

20678890 is a wasteful number, since it uses less digits than its factorization.

20678890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3017.

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

The square root of 20678890 is about 4547.4047543626. The cubic root of 20678890 is about 274.4789693721.

The spelling of 20678890 in words is "twenty million, six hundred seventy-eight thousand, eight hundred ninety".