20971519 has 4 divisors (see below), whose sum is σ = 20984560. Its totient is φ = 20958480.

The previous prime is 20971507. The next prime is 20971529. The reversal of 20971519 is 91517902.

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 20971519 - 2¹¹ = 20969471 is a prime.

It is a super-2 number, since 2×20971519² = 879609218334722, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 8 and base 16.

It is a zygodrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20971529) by changing a digit.

Being equal to 20×2²⁰-1, it is a Woodall number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3702 + ... + 7459.

It is an arithmetic number, because the mean of its divisors is an integer number (5246140).

Almost surely, 2^20971519 is an apocalyptic number.

20971519 is a deficient number, since it is larger than the sum of its proper divisors (13041).

20971519 is a wasteful number, since it uses less digits than its factorization.

20971519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13040.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 20971519 is about 4579.4671087366. The cubic root of 20971519 is about 275.7676359409.

The spelling of 20971519 in words is "twenty million, nine hundred seventy-one thousand, five hundred nineteen".