21255351403337 has 2 divisors, whose sum is σ = 21255351403338. Its totient is φ = 21255351403336.

The previous prime is 21255351403283. The next prime is 21255351403471. The reversal of 21255351403337 is 73330415355212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18153769004176 + 3101582399161 = 4260724^2 + 1761131^2 .

It is a cyclic number.

It is not a de Polignac number, because 21255351403337 - 2²⁶ = 21255284294473 is a prime.

It is not a weakly prime, because it can be changed into another prime (21255351403537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627675701668 + 10627675701669.

It is an arithmetic number, because the mean of its divisors is an integer number (10627675701669).

Almost surely, 2^{21255351403337} is an apocalyptic number.

It is an amenable number.

21255351403337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255351403337 is an equidigital number, since it uses as much as digits as its factorization.

21255351403337 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134000, while the sum is 44.

Adding to 21255351403337 its reverse (73330415355212), we get a palindrome (94585766758549).

The spelling of 21255351403337 in words is "twenty-one trillion, two hundred fifty-five billion, three hundred fifty-one million, four hundred three thousand, three hundred thirty-seven".