20787804 has 36 divisors (see below), whose sum is σ = 55639584. Its totient is φ = 6521472.

The previous prime is 20787803. The next prime is 20787827. The reversal of 20787804 is 40878702.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20787803) 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 11 ways as a sum of consecutive naturals, for example, 16372 + ... + 17595.

It is an arithmetic number, because the mean of its divisors is an integer number (1545544).

Almost surely, 2^20787804 is an apocalyptic number.

It is an amenable number.

20787804 is an abundant number, since it is smaller than the sum of its proper divisors (34851780).

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

20787804 is a wasteful number, since it uses less digits than its factorization.

20787804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33994 (or 33989 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 20787804 is about 4559.3644293914. The cubic root of 20787804 is about 274.9600118164.

The spelling of 20787804 in words is "twenty million, seven hundred eighty-seven thousand, eight hundred four".