20445900 has 144 divisors (see below), whose sum is σ = 66245760. Its totient is φ = 4838400.

The previous prime is 20445889. The next prime is 20445923. The reversal of 20445900 is 954402.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 96795 + ... + 97005.

It is an arithmetic number, because the mean of its divisors is an integer number (460040).

Almost surely, 2^20445900 is an apocalyptic number.

20445900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20445900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33122880).

20445900 is an abundant number, since it is smaller than the sum of its proper divisors (45799860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20445900 is a wasteful number, since it uses less digits than its factorization.

20445900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264 (or 257 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 20445900 is about 4521.7142766875. The cubic root of 20445900 is about 273.4442176853. Note that the first 3 decimals are identical.

It can be divided in two parts, 204 and 45900, that multiplied together give a square (9363600 = 3060²).

The spelling of 20445900 in words is "twenty million, four hundred forty-five thousand, nine hundred".