21255351403336 has 64 divisors (see below), whose sum is σ = 40835030227200. Its totient is φ = 10366678038528.

The previous prime is 21255351403283. The next prime is 21255351403337. The reversal of 21255351403336 is 63330415355212.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a junction number, because it is equal to n+sod(n) for n = 21255351403292 and 21255351403301.

It is not an unprimeable number, because it can be changed into a prime (21255351403337) 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, 989208385 + ... + 989229871.

It is an arithmetic number, because the mean of its divisors is an integer number (638047347300).

Almost surely, 2^{21255351403336} is an apocalyptic number.

It is an amenable number.

21255351403336 is a deficient number, since it is larger than the sum of its proper divisors (19579678823864).

21255351403336 is a wasteful number, since it uses less digits than its factorization.

21255351403336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25238 (or 25234 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 43.

Adding to 21255351403336 its reverse (63330415355212), we get a palindrome (84585766758548).

The spelling of 21255351403336 in words is "twenty-one trillion, two hundred fifty-five billion, three hundred fifty-one million, four hundred three thousand, three hundred thirty-six".