20904719 has 4 divisors (see below), whose sum is σ = 22805160. Its totient is φ = 19004280.

The previous prime is 20904701. The next prime is 20904733. The reversal of 20904719 is 91740902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20904719 is a prime.

It is a super-2 number, since 2×20904719² = 874014552937922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20904019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 950204 + ... + 950225.

It is an arithmetic number, because the mean of its divisors is an integer number (5701290).

Almost surely, 2^20904719 is an apocalyptic number.

20904719 is a deficient number, since it is larger than the sum of its proper divisors (1900441).

20904719 is a wasteful number, since it uses less digits than its factorization.

20904719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900440.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20904719 is about 4572.1678665596. The cubic root of 20904719 is about 275.4745261651.

The spelling of 20904719 in words is "twenty million, nine hundred four thousand, seven hundred nineteen".