20771669 has 4 divisors (see below), whose sum is σ = 20833644. Its totient is φ = 20709696.

The previous prime is 20771657. The next prime is 20771683. The reversal of 20771669 is 96617702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96617702 = 2 ⋅48308851.

It can be written as a sum of positive squares in 2 ways, for example, as 4571044 + 16200625 = 2138^2 + 4025^2 .

It is a cyclic number.

It is not a de Polignac number, because 20771669 - 2²⁴ = 3994453 is a prime.

It is a super-2 number, since 2×20771669² = 862924466091122, 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 (20771629) 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, 30482 + ... + 31155.

It is an arithmetic number, because the mean of its divisors is an integer number (5208411).

Almost surely, 2^20771669 is an apocalyptic number.

It is an amenable number.

20771669 is a deficient number, since it is larger than the sum of its proper divisors (61975).

20771669 is an equidigital number, since it uses as much as digits as its factorization.

20771669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61974.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 20771669 is about 4557.5946506902. The cubic root of 20771669 is about 274.8888542582. Note that the first 4 decimals are identical.

The spelling of 20771669 in words is "twenty million, seven hundred seventy-one thousand, six hundred sixty-nine".