21917449027 has 2 divisors, whose sum is σ = 21917449028. Its totient is φ = 21917449026.

The previous prime is 21917448991. The next prime is 21917449067. The reversal of 21917449027 is 72094471912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21917449027 - 2⁷ = 21917448899 is a prime.

It is a super-2 number, since 2×21917449027² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21917449067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10958724513 + 10958724514.

It is an arithmetic number, because the mean of its divisors is an integer number (10958724514).

Almost surely, 2^21917449027 is an apocalyptic number.

21917449027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21917449027 is an equidigital number, since it uses as much as digits as its factorization.

21917449027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 21917449027 in words is "twenty-one billion, nine hundred seventeen million, four hundred forty-nine thousand, twenty-seven".