20680784 has 10 divisors (see below), whose sum is σ = 40069050. Its totient is φ = 10340384.

The previous prime is 20680747. The next prime is 20680787. The reversal of 20680784 is 48708602.

It can be written as a sum of positive squares in only one way, i.e., 15054400 + 5626384 = 3880^2 + 2372^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20680787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 646259 + ... + 646290.

It is an arithmetic number, because the mean of its divisors is an integer number (4006905).

Almost surely, 2^20680784 is an apocalyptic number.

It is an amenable number.

20680784 is a deficient number, since it is larger than the sum of its proper divisors (19388266).

20680784 is a wasteful number, since it uses less digits than its factorization.

20680784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1292557 (or 1292551 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 20680784 is about 4547.6130002453. The cubic root of 20680784 is about 274.4873490497.

The spelling of 20680784 in words is "twenty million, six hundred eighty thousand, seven hundred eighty-four".