21230255369 has 2 divisors, whose sum is σ = 21230255370. Its totient is φ = 21230255368.

The previous prime is 21230255329. The next prime is 21230255381. The reversal of 21230255369 is 96355203212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21211009600 + 19245769 = 145640^2 + 4387^2 .

It is a cyclic number.

It is not a de Polignac number, because 21230255369 - 2¹⁶ = 21230189833 is a prime.

It is a super-2 number, since 2×21230255369² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21230255329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615127684 + 10615127685.

It is an arithmetic number, because the mean of its divisors is an integer number (10615127685).

Almost surely, 2^21230255369 is an apocalyptic number.

It is an amenable number.

21230255369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230255369 is an equidigital number, since it uses as much as digits as its factorization.

21230255369 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 38.

The spelling of 21230255369 in words is "twenty-one billion, two hundred thirty million, two hundred fifty-five thousand, three hundred sixty-nine".