20916719 has 4 divisors (see below), whose sum is σ = 20934144. Its totient is φ = 20899296.

The previous prime is 20916713. The next prime is 20916767. The reversal of 20916719 is 91761902.

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

It is a cyclic number.

It is not a de Polignac number, because 20916719 - 2²⁴ = 4139503 is a prime.

It is a super-2 number, since 2×20916719² = 875018267449922, 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 (20916713) 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, 6767 + ... + 9360.

It is an arithmetic number, because the mean of its divisors is an integer number (5233536).

Almost surely, 2^20916719 is an apocalyptic number.

20916719 is a deficient number, since it is larger than the sum of its proper divisors (17425).

20916719 is a wasteful number, since it uses less digits than its factorization.

20916719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17424.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 20916719 is about 4573.4799660652. The cubic root of 20916719 is about 275.5272265783.

The spelling of 20916719 in words is "twenty million, nine hundred sixteen thousand, seven hundred nineteen".