20455578 has 80 divisors (see below), whose sum is σ = 53909856. Its totient is φ = 5715360.

The previous prime is 20455559. The next prime is 20455601. The reversal of 20455578 is 87555402.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 22725 + ... + 23607.

Almost surely, 2^20455578 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20455578, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26954928).

20455578 is an abundant number, since it is smaller than the sum of its proper divisors (33454278).

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

20455578 is a wasteful number, since it uses less digits than its factorization.

20455578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921 (or 912 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 36.

The square root of 20455578 is about 4522.7843194209. The cubic root of 20455578 is about 273.4873555221.

The spelling of 20455578 in words is "twenty million, four hundred fifty-five thousand, five hundred seventy-eight".