21636054 has 48 divisors (see below), whose sum is σ = 53374464. Its totient is φ = 6270000.

The previous prime is 21636049. The next prime is 21636073. The reversal of 21636054 is 45063612.

21636054 is a `hidden beast` number, since 21 + 636 + 0 + 5 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2179 + ... + 6929.

It is an arithmetic number, because the mean of its divisors is an integer number (1111968).

Almost surely, 2^21636054 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21636054, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26687232).

21636054 is an abundant number, since it is smaller than the sum of its proper divisors (31738410).

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

21636054 is a wasteful number, since it uses less digits than its factorization.

21636054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4793 (or 4790 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 21636054 is about 4651.4571910316. The cubic root of 21636054 is about 278.6501955904.

Adding to 21636054 its reverse (45063612), we get a palindrome (66699666).

The spelling of 21636054 in words is "twenty-one million, six hundred thirty-six thousand, fifty-four".