20203656 has 64 divisors (see below), whose sum is σ = 55710720. Its totient is φ = 6054720.

The previous prime is 20203643. The next prime is 20203657. The reversal of 20203656 is 65630202.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20203657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26821 + ... + 27563.

It is an arithmetic number, because the mean of its divisors is an integer number (870480).

Almost surely, 2^20203656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20203656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27855360).

20203656 is an abundant number, since it is smaller than the sum of its proper divisors (35507064).

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

20203656 is a wasteful number, since it uses less digits than its factorization.

20203656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866 (or 862 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 20203656 is about 4494.8477171090. The cubic root of 20203656 is about 272.3599976622.

Adding to 20203656 its reverse (65630202), we get a palindrome (85833858).

The spelling of 20203656 in words is "twenty million, two hundred three thousand, six hundred fifty-six".