20780055 has 24 divisors (see below), whose sum is σ = 36252528. Its totient is φ = 11010816.

The previous prime is 20780047. The next prime is 20780057. The reversal of 20780055 is 55008702.

It is a happy number.

It is not a de Polignac number, because 20780055 - 2³ = 20780047 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780057) 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, 5919 + ... + 8751.

It is an arithmetic number, because the mean of its divisors is an integer number (1510522).

Almost surely, 2^20780055 is an apocalyptic number.

20780055 is a deficient number, since it is larger than the sum of its proper divisors (15472473).

20780055 is a wasteful number, since it uses less digits than its factorization.

20780055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3007 (or 3004 counting only the distinct ones).

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

The square root of 20780055 is about 4558.5145606875. The cubic root of 20780055 is about 274.9258422630.

Adding to 20780055 its reverse (55008702), we get a palindrome (75788757).

The spelling of 20780055 in words is "twenty million, seven hundred eighty thousand, fifty-five".