21955236 has 24 divisors (see below), whose sum is σ = 51313920. Its totient is φ = 7306272.

The previous prime is 21955231. The next prime is 21955247. The reversal of 21955236 is 63255912.

It is a junction number, because it is equal to n+sod(n) for n = 21955197 and 21955206.

It is not an unprimeable number, because it can be changed into a prime (21955231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8845 + ... + 11051.

It is an arithmetic number, because the mean of its divisors is an integer number (2138080).

Almost surely, 2^21955236 is an apocalyptic number.

It is an amenable number.

21955236 is an abundant number, since it is smaller than the sum of its proper divisors (29358684).

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

21955236 is a wasteful number, since it uses less digits than its factorization.

21955236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043 (or 3041 counting only the distinct ones).

The product of its digits is 16200, while the sum is 33.

The square root of 21955236 is about 4685.6414715597. The cubic root of 21955236 is about 280.0137578274.

It can be divided in two parts, 219 and 55236, that added together give a palindrome (55455).

The spelling of 21955236 in words is "twenty-one million, nine hundred fifty-five thousand, two hundred thirty-six".