21321364436 has 12 divisors (see below), whose sum is σ = 39507234228. Its totient is φ = 10033583232.

The previous prime is 21321364423. The next prime is 21321364451. The reversal of 21321364436 is 63446312312.

It can be written as a sum of positive squares in 2 ways, for example, as 6305312836 + 15016051600 = 79406^2 + 122540^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21321364396 and 21321364405.

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, 156774671 + ... + 156774806.

It is an arithmetic number, because the mean of its divisors is an integer number (3292269519).

Almost surely, 2^21321364436 is an apocalyptic number.

It is an amenable number.

21321364436 is a deficient number, since it is larger than the sum of its proper divisors (18185869792).

21321364436 is a wasteful number, since it uses less digits than its factorization.

21321364436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313549498 (or 313549496 counting only the distinct ones).

The product of its digits is 62208, while the sum is 35.

Adding to 21321364436 its reverse (63446312312), we get a palindrome (84767676748).

The spelling of 21321364436 in words is "twenty-one billion, three hundred twenty-one million, three hundred sixty-four thousand, four hundred thirty-six".