21401185236 has 12 divisors (see below), whose sum is σ = 49936098912. Its totient is φ = 7133728408.

The previous prime is 21401185217. The next prime is 21401185243. The reversal of 21401185236 is 63258110412.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21401185197 and 21401185206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 891716040 + ... + 891716063.

It is an arithmetic number, because the mean of its divisors is an integer number (4161341576).

Almost surely, 2^21401185236 is an apocalyptic number.

It is an amenable number.

21401185236 is an abundant number, since it is smaller than the sum of its proper divisors (28534913676).

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

21401185236 is a wasteful number, since it uses less digits than its factorization.

21401185236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783432110 (or 1783432108 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

Adding to 21401185236 its reverse (63258110412), we get a palindrome (84659295648).

The spelling of 21401185236 in words is "twenty-one billion, four hundred one million, one hundred eighty-five thousand, two hundred thirty-six".