21601384841287 has 2 divisors, whose sum is σ = 21601384841288. Its totient is φ = 21601384841286.

The previous prime is 21601384841263. The next prime is 21601384841383. The reversal of 21601384841287 is 78214848310612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21601384841287 - 2¹¹ = 21601384839239 is a prime.

It is a super-2 number, since 2×21601384841287² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21601384841887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800692420643 + 10800692420644.

It is an arithmetic number, because the mean of its divisors is an integer number (10800692420644).

Almost surely, 2^{21601384841287} is an apocalyptic number.

21601384841287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21601384841287 is an equidigital number, since it uses as much as digits as its factorization.

21601384841287 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4128768, while the sum is 55.

The spelling of 21601384841287 in words is "twenty-one trillion, six hundred one billion, three hundred eighty-four million, eight hundred forty-one thousand, two hundred eighty-seven".