20107780 has 72 divisors (see below), whose sum is σ = 53089344. Its totient is φ = 6262080.

The previous prime is 20107771. The next prime is 20107807. The reversal of 20107780 is 8770102.

20107780 = 116² + 117² + ... + 395².

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16347 + ... + 17533.

It is an arithmetic number, because the mean of its divisors is an integer number (737352).

Almost surely, 2^20107780 is an apocalyptic number.

20107780 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 20107780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26544672).

20107780 is an abundant number, since it is smaller than the sum of its proper divisors (32981564).

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

20107780 is a wasteful number, since it uses less digits than its factorization.

20107780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1225 (or 1212 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 25.

The square root of 20107780 is about 4484.1699343357. The cubic root of 20107780 is about 271.9284882650.

Adding to 20107780 its reverse (8770102), we get a palindrome (28877882).

The spelling of 20107780 in words is "twenty million, one hundred seven thousand, seven hundred eighty".