20784913 has 2 divisors, whose sum is σ = 20784914. Its totient is φ = 20784912.

The previous prime is 20784901. The next prime is 20784919. The reversal of 20784913 is 31948702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14190289 + 6594624 = 3767^2 + 2568^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20784913 is a prime.

It is not a weakly prime, because it can be changed into another prime (20784919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10392456 + 10392457.

It is an arithmetic number, because the mean of its divisors is an integer number (10392457).

Almost surely, 2^20784913 is an apocalyptic number.

It is an amenable number.

20784913 is a deficient number, since it is larger than the sum of its proper divisors (1).

20784913 is an equidigital number, since it uses as much as digits as its factorization.

20784913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20784913 is about 4559.0473785650. The cubic root of 20784913 is about 274.9472648191.

The spelling of 20784913 in words is "twenty million, seven hundred eighty-four thousand, nine hundred thirteen".