20780636 has 12 divisors (see below), whose sum is σ = 36413328. Its totient is φ = 10376832.

The previous prime is 20780581. The next prime is 20780657. The reversal of 20780636 is 63608702.

It is a congruent number.

It is an unprimeable number.

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, 620 + ... + 6476.

It is an arithmetic number, because the mean of its divisors is an integer number (3034444).

Almost surely, 2^20780636 is an apocalyptic number.

It is an amenable number.

20780636 is a deficient number, since it is larger than the sum of its proper divisors (15632692).

20780636 is a wasteful number, since it uses less digits than its factorization.

20780636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6748 (or 6746 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20780636 is about 4558.5782871417. The cubic root of 20780636 is about 274.9284045024.

The spelling of 20780636 in words is "twenty million, seven hundred eighty thousand, six hundred thirty-six".