21916987327 has 2 divisors, whose sum is σ = 21916987328. Its totient is φ = 21916987326.

The previous prime is 21916987277. The next prime is 21916987361. The reversal of 21916987327 is 72378961912.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21916987327 - 2¹⁵ = 21916954559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21916982327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10958493663 + 10958493664.

It is an arithmetic number, because the mean of its divisors is an integer number (10958493664).

Almost surely, 2^21916987327 is an apocalyptic number.

21916987327 is a deficient number, since it is larger than the sum of its proper divisors (1).

21916987327 is an equidigital number, since it uses as much as digits as its factorization.

21916987327 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 55.

The spelling of 21916987327 in words is "twenty-one billion, nine hundred sixteen million, nine hundred eighty-seven thousand, three hundred twenty-seven".