21647450269 has 2 divisors, whose sum is σ = 21647450270. Its totient is φ = 21647450268.

The previous prime is 21647450197. The next prime is 21647450273. The reversal of 21647450269 is 96205474612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20185305625 + 1462144644 = 142075^2 + 38238^2 .

It is a cyclic number.

It is not a de Polignac number, because 21647450269 - 2¹⁵ = 21647417501 is a prime.

It is a super-2 number, since 2×21647450269² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21647450299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10823725134 + 10823725135.

It is an arithmetic number, because the mean of its divisors is an integer number (10823725135).

Almost surely, 2^21647450269 is an apocalyptic number.

It is an amenable number.

21647450269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21647450269 is an equidigital number, since it uses as much as digits as its factorization.

21647450269 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 46.

The spelling of 21647450269 in words is "twenty-one billion, six hundred forty-seven million, four hundred fifty thousand, two hundred sixty-nine".