20257243 has 4 divisors (see below), whose sum is σ = 20268360. Its totient is φ = 20246128.

The previous prime is 20257219. The next prime is 20257247. The reversal of 20257243 is 34275202.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20257243 - 2²¹ = 18160091 is a prime.

It is a super-2 number, since 2×20257243² = 820711787922098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20257247) 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, 2113 + ... + 6706.

It is an arithmetic number, because the mean of its divisors is an integer number (5067090).

Almost surely, 2^20257243 is an apocalyptic number.

20257243 is a deficient number, since it is larger than the sum of its proper divisors (11117).

20257243 is an equidigital number, since it uses as much as digits as its factorization.

20257243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11116.

The product of its (nonzero) digits is 3360, while the sum is 25.

The square root of 20257243 is about 4500.8047058276. The cubic root of 20257243 is about 272.6005823460.

The spelling of 20257243 in words is "twenty million, two hundred fifty-seven thousand, two hundred forty-three".