21210661241436 has 96 divisors (see below), whose sum is σ = 51467263303680. Its totient is φ = 6791372812800.

The previous prime is 21210661241431. The next prime is 21210661241449. The reversal of 21210661241436 is 63414216601212.

It is a junction number, because it is equal to n+sod(n) for n = 21210661241394 and 21210661241403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210661241431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 518844045 + ... + 518884923.

It is an arithmetic number, because the mean of its divisors is an integer number (536117326080).

Almost surely, 2^{21210661241436} is an apocalyptic number.

It is an amenable number.

21210661241436 is an abundant number, since it is smaller than the sum of its proper divisors (30256602062244).

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

21210661241436 is a wasteful number, since it uses less digits than its factorization.

21210661241436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51235 (or 51233 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 39.

Adding to 21210661241436 its reverse (63414216601212), we get a palindrome (84624877842648).

The spelling of 21210661241436 in words is "twenty-one trillion, two hundred ten billion, six hundred sixty-one million, two hundred forty-one thousand, four hundred thirty-six".