20857269 has 16 divisors (see below), whose sum is σ = 29401280. Its totient is φ = 13115520.

The previous prime is 20857247. The next prime is 20857313. The reversal of 20857269 is 96275802.

It is a happy number.

It is not a de Polignac number, because 20857269 - 2¹¹ = 20855221 is a prime.

It is a super-2 number, since 2×20857269² = 870051340276722, 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 (20857469) 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 15 ways as a sum of consecutive naturals, for example, 15129 + ... + 16449.

It is an arithmetic number, because the mean of its divisors is an integer number (1837580).

Almost surely, 2^20857269 is an apocalyptic number.

It is an amenable number.

20857269 is a deficient number, since it is larger than the sum of its proper divisors (8544011).

20857269 is a wasteful number, since it uses less digits than its factorization.

20857269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620.

The product of its (nonzero) digits is 60480, while the sum is 39.

The square root of 20857269 is about 4566.9759141033. The cubic root of 20857269 is about 275.2659421834.

The spelling of 20857269 in words is "twenty million, eight hundred fifty-seven thousand, two hundred sixty-nine".