20677705 has 4 divisors (see below), whose sum is σ = 24813252. Its totient is φ = 16542160.

The previous prime is 20677693. The next prime is 20677717. The reversal of 20677705 is 50777602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50777602 = 2 ⋅25388801.

It is an interprime number because it is at equal distance from previous prime (20677693) and next prime (20677717).

It can be written as a sum of positive squares in 2 ways, for example, as 15515721 + 5161984 = 3939^2 + 2272^2 .

It is not a de Polignac number, because 20677705 - 2⁷ = 20677577 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 2067766 + ... + 2067775.

It is an arithmetic number, because the mean of its divisors is an integer number (6203313).

Almost surely, 2^20677705 is an apocalyptic number.

It is an amenable number.

20677705 is a deficient number, since it is larger than the sum of its proper divisors (4135547).

20677705 is an equidigital number, since it uses as much as digits as its factorization.

20677705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4135546.

The product of its (nonzero) digits is 20580, while the sum is 34.

The square root of 20677705 is about 4547.2744583981. The cubic root of 20677705 is about 274.4737262829.

The spelling of 20677705 in words is "twenty million, six hundred seventy-seven thousand, seven hundred five".