20995775 has 6 divisors (see below), whose sum is σ = 26034792. Its totient is φ = 16796600.

The previous prime is 20995771. The next prime is 20995781. The reversal of 20995775 is 57759902.

It is not a de Polignac number, because 20995775 - 2² = 20995771 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20995771) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 419891 + ... + 419940.

It is an arithmetic number, because the mean of its divisors is an integer number (4339132).

Almost surely, 2^20995775 is an apocalyptic number.

20995775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20995775 is a deficient number, since it is larger than the sum of its proper divisors (5039017).

20995775 is an equidigital number, since it uses as much as digits as its factorization.

20995775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 839841 (or 839836 counting only the distinct ones).

The product of its (nonzero) digits is 198450, while the sum is 44.

The square root of 20995775 is about 4582.1146864739. The cubic root of 20995775 is about 275.8739140882.

The spelling of 20995775 in words is "twenty million, nine hundred ninety-five thousand, seven hundred seventy-five".