21231243603636 has 48 divisors (see below), whose sum is σ = 54044567290560. Its totient is φ = 6433543307520.

The previous prime is 21231243603631. The next prime is 21231243603637. The reversal of 21231243603636 is 63630634213212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231243603631) 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, 3070560 + ... + 7203528.

It is an arithmetic number, because the mean of its divisors is an integer number (1125928485220).

Almost surely, 2^{21231243603636} is an apocalyptic number.

It is an amenable number.

21231243603636 is an abundant number, since it is smaller than the sum of its proper divisors (32813323686924).

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

21231243603636 is a wasteful number, since it uses less digits than its factorization.

21231243603636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4171904 (or 4171902 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 42.

Adding to 21231243603636 its reverse (63630634213212), we get a palindrome (84861877816848).

The spelling of 21231243603636 in words is "twenty-one trillion, two hundred thirty-one billion, two hundred forty-three million, six hundred three thousand, six hundred thirty-six".