20055780 has 72 divisors (see below), whose sum is σ = 61780992. Its totient is φ = 5265216.

The previous prime is 20055769. The next prime is 20055781. The reversal of 20055780 is 8755002.

It is a happy number.

It is a super-2 number, since 2×20055780² = 804468622816800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20055781) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11229 + ... + 12891.

Almost surely, 2^20055780 is an apocalyptic number.

20055780 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 20055780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30890496).

20055780 is an abundant number, since it is smaller than the sum of its proper divisors (41725212).

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

20055780 is a wasteful number, since it uses less digits than its factorization.

20055780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1745 (or 1740 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 20055780 is about 4478.3680063166. The cubic root of 20055780 is about 271.6938777784.

The spelling of 20055780 in words is "twenty million, fifty-five thousand, seven hundred eighty".