20256769 has 4 divisors (see below), whose sum is σ = 21814996. Its totient is φ = 18698544.

The previous prime is 20256763. The next prime is 20256811. The reversal of 20256769 is 96765202.

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 5702544 + 14554225 = 2388^2 + 3815^2 .

It is a cyclic number.

It is not a de Polignac number, because 20256769 - 2⁵ = 20256737 is a prime.

It is a super-2 number, since 2×20256769² = 820673380638722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20256763) 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, 779094 + ... + 779119.

It is an arithmetic number, because the mean of its divisors is an integer number (5453749).

Almost surely, 2^20256769 is an apocalyptic number.

It is an amenable number.

20256769 is a deficient number, since it is larger than the sum of its proper divisors (1558227).

20256769 is a wasteful number, since it uses less digits than its factorization.

20256769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1558226.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 20256769 is about 4500.7520482693. The cubic root of 20256769 is about 272.5984561323.

It can be divided in two parts, 20256 and 769, that added together give a square (21025 = 145²).

The spelling of 20256769 in words is "twenty million, two hundred fifty-six thousand, seven hundred sixty-nine".