20023556 has 18 divisors (see below), whose sum is σ = 40762638. Its totient is φ = 8581440.

The previous prime is 20023537. The next prime is 20023561. The reversal of 20023556 is 65532002.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19945156 + 78400 = 4466^2 + 280^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50885 + ... + 51276.

It is an arithmetic number, because the mean of its divisors is an integer number (2264591).

Almost surely, 2^20023556 is an apocalyptic number.

It is an amenable number.

20023556 is an abundant number, since it is smaller than the sum of its proper divisors (20739082).

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

20023556 is a wasteful number, since it uses less digits than its factorization.

20023556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102179 (or 102170 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 20023556 is about 4474.7688208443. The cubic root of 20023556 is about 271.5482878839.

Adding to 20023556 its reverse (65532002), we get a palindrome (85555558).

The spelling of 20023556 in words is "twenty million, twenty-three thousand, five hundred fifty-six".