20999719 has 4 divisors (see below), whose sum is σ = 22615096. Its totient is φ = 19384344.

The previous prime is 20999711. The next prime is 20999723. The reversal of 20999719 is 91799902.

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 20999719 - 2³ = 20999711 is a prime.

It is a super-2 number, since 2×20999719² = 881976396157922, 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 (20999711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807669 + ... + 807694.

It is an arithmetic number, because the mean of its divisors is an integer number (5653774).

Almost surely, 2^20999719 is an apocalyptic number.

20999719 is a deficient number, since it is larger than the sum of its proper divisors (1615377).

20999719 is a wasteful number, since it uses less digits than its factorization.

20999719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615376.

The product of its (nonzero) digits is 91854, while the sum is 46.

The square root of 20999719 is about 4582.5450352397. The cubic root of 20999719 is about 275.8911870649.

The spelling of 20999719 in words is "twenty million, nine hundred ninety-nine thousand, seven hundred nineteen".