20969617 has 4 divisors (see below), whose sum is σ = 20987316. Its totient is φ = 20951920.

The previous prime is 20969527. The next prime is 20969623. The reversal of 20969617 is 71696902.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5216656 + 15752961 = 2284^2 + 3969^2 .

It is a cyclic number.

It is not a de Polignac number, because 20969617 - 2⁷ = 20969489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20969617.

It is not an unprimeable number, because it can be changed into a prime (20969677) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6934 + ... + 9487.

It is an arithmetic number, because the mean of its divisors is an integer number (5246829).

Almost surely, 2^20969617 is an apocalyptic number.

It is an amenable number.

20969617 is a deficient number, since it is larger than the sum of its proper divisors (17699).

20969617 is a wasteful number, since it uses less digits than its factorization.

20969617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17698.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 20969617 is about 4579.2594379441. The cubic root of 20969617 is about 275.7592988258.

The spelling of 20969617 in words is "twenty million, nine hundred sixty-nine thousand, six hundred seventeen".