20005545 has 16 divisors (see below), whose sum is σ = 36581760. Its totient is φ = 9145344.

The previous prime is 20005541. The next prime is 20005589. The reversal of 20005545 is 54550002.

It is not a de Polignac number, because 20005545 - 2² = 20005541 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20005541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95160 + ... + 95369.

It is an arithmetic number, because the mean of its divisors is an integer number (2286360).

Almost surely, 2^20005545 is an apocalyptic number.

It is an amenable number.

20005545 is a deficient number, since it is larger than the sum of its proper divisors (16576215).

20005545 is a wasteful number, since it uses less digits than its factorization.

20005545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190544.

The product of its (nonzero) digits is 1000, while the sum is 21.

The square root of 20005545 is about 4472.7558618820. The cubic root of 20005545 is about 271.4668450843.

Adding to 20005545 its reverse (54550002), we get a palindrome (74555547).

The spelling of 20005545 in words is "twenty million, five thousand, five hundred forty-five".