20445553 has 4 divisors (see below), whose sum is σ = 20780788. Its totient is φ = 20110320.

The previous prime is 20445541. The next prime is 20445583. The reversal of 20445553 is 35554402.

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 10909809 + 9535744 = 3303^2 + 3088^2 .

It is a cyclic number.

It is not a de Polignac number, because 20445553 - 2⁵ = 20445521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20445533) 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, 167526 + ... + 167647.

It is an arithmetic number, because the mean of its divisors is an integer number (5195197).

Almost surely, 2^20445553 is an apocalyptic number.

It is an amenable number.

20445553 is a deficient number, since it is larger than the sum of its proper divisors (335235).

20445553 is an equidigital number, since it uses as much as digits as its factorization.

20445553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335234.

The product of its (nonzero) digits is 12000, while the sum is 28.

The square root of 20445553 is about 4521.6759061215. The cubic root of 20445553 is about 273.4426707463.

Adding to 20445553 its reverse (35554402), we get a palindrome (55999955).

The spelling of 20445553 in words is "twenty million, four hundred forty-five thousand, five hundred fifty-three".