20448557 has 4 divisors (see below), whose sum is σ = 20457756. Its totient is φ = 20439360.

The previous prime is 20448553. The next prime is 20448581. The reversal of 20448557 is 75584402.

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 can be written as a sum of positive squares in 2 ways, for example, as 10329796 + 10118761 = 3214^2 + 3181^2 .

It is a cyclic number.

It is not a de Polignac number, because 20448557 - 2² = 20448553 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20448553) 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, 1043 + ... + 6479.

It is an arithmetic number, because the mean of its divisors is an integer number (5114439).

Almost surely, 2^20448557 is an apocalyptic number.

It is an amenable number.

20448557 is a deficient number, since it is larger than the sum of its proper divisors (9199).

20448557 is an equidigital number, since it uses as much as digits as its factorization.

20448557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9198.

The product of its (nonzero) digits is 44800, while the sum is 35.

The square root of 20448557 is about 4522.0080716425. The cubic root of 20448557 is about 273.4560621108.

It can be divided in two parts, 2044 and 8557, that added together give a palindrome (10601).

The spelling of 20448557 in words is "twenty million, four hundred forty-eight thousand, five hundred fifty-seven".