21645167627 has 2 divisors, whose sum is σ = 21645167628. Its totient is φ = 21645167626.

The previous prime is 21645167611. The next prime is 21645167641. The reversal of 21645167627 is 72676154612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21645167627 - 2⁴ = 21645167611 is a prime.

It is a super-2 number, since 2×21645167627² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21647167627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10822583813 + 10822583814.

It is an arithmetic number, because the mean of its divisors is an integer number (10822583814).

Almost surely, 2^21645167627 is an apocalyptic number.

21645167627 is a deficient number, since it is larger than the sum of its proper divisors (1).

21645167627 is an equidigital number, since it uses as much as digits as its factorization.

21645167627 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 47.

The spelling of 21645167627 in words is "twenty-one billion, six hundred forty-five million, one hundred sixty-seven thousand, six hundred twenty-seven".