20776661 has 4 divisors (see below), whose sum is σ = 21117324. Its totient is φ = 20436000.

The previous prime is 20776631. The next prime is 20776663. The reversal of 20776661 is 16667702.

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 2235025 + 18541636 = 1495^2 + 4306^2 .

It is a cyclic number.

It is not a de Polignac number, because 20776661 - 2⁶ = 20776597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20776663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170240 + ... + 170361.

It is an arithmetic number, because the mean of its divisors is an integer number (5279331).

Almost surely, 2^20776661 is an apocalyptic number.

It is an amenable number.

20776661 is a deficient number, since it is larger than the sum of its proper divisors (340663).

20776661 is an equidigital number, since it uses as much as digits as its factorization.

20776661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340662.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 20776661 is about 4558.1422750941. The cubic root of 20776661 is about 274.9108735969.

The spelling of 20776661 in words is "twenty million, seven hundred seventy-six thousand, six hundred sixty-one".