20861055 has 12 divisors (see below), whose sum is σ = 36159240. Its totient is φ = 11125872.

The previous prime is 20861051. The next prime is 20861077. The reversal of 20861055 is 55016802.

It is not a de Polignac number, because 20861055 - 2² = 20861051 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20861051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 231745 + ... + 231834.

It is an arithmetic number, because the mean of its divisors is an integer number (3013270).

Almost surely, 2^20861055 is an apocalyptic number.

20861055 is a deficient number, since it is larger than the sum of its proper divisors (15298185).

20861055 is a wasteful number, since it uses less digits than its factorization.

20861055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463590 (or 463587 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 20861055 is about 4567.3903927735. The cubic root of 20861055 is about 275.2825965499.

Adding to 20861055 its reverse (55016802), we get a palindrome (75877857).

The spelling of 20861055 in words is "twenty million, eight hundred sixty-one thousand, fifty-five".