20257513 has 4 divisors (see below), whose sum is σ = 20316240. Its totient is φ = 20198788.

The previous prime is 20257493. The next prime is 20257519. The reversal of 20257513 is 31575202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31575202 = 2 ⋅15787601.

It is a cyclic number.

It is not a de Polignac number, because 20257513 - 2⁵ = 20257481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20257519) 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, 28843 + ... + 29536.

It is an arithmetic number, because the mean of its divisors is an integer number (5079060).

Almost surely, 2^20257513 is an apocalyptic number.

It is an amenable number.

20257513 is a deficient number, since it is larger than the sum of its proper divisors (58727).

20257513 is an equidigital number, since it uses as much as digits as its factorization.

20257513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58726.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 20257513 is about 4500.8347003639. The cubic root of 20257513 is about 272.6017934656.

The spelling of 20257513 in words is "twenty million, two hundred fifty-seven thousand, five hundred thirteen".