20045109 has 12 divisors (see below), whose sum is σ = 30576224. Its totient is φ = 11442624.

The previous prime is 20045101. The next prime is 20045117. The reversal of 20045109 is 90154002.

It is an interprime number because it is at equal distance from previous prime (20045101) and next prime (20045117).

It is not a de Polignac number, because 20045109 - 2³ = 20045101 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20045101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20029 + ... + 21005.

Almost surely, 2^20045109 is an apocalyptic number.

It is an amenable number.

20045109 is a deficient number, since it is larger than the sum of its proper divisors (10531115).

20045109 is an frugal number, since it uses more digits than its factorization.

20045109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1964 (or 987 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20045109 is about 4477.1764539719. The cubic root of 20045109 is about 271.6456828653.

Multiplying 20045109 by its sum of digits (21), we get a square (420947289 = 20517²).

20045109 divided by its sum of digits (21) gives a square (954529 = 977²).

The spelling of 20045109 in words is "twenty million, forty-five thousand, one hundred nine".