21016731727 has 2 divisors, whose sum is σ = 21016731728. Its totient is φ = 21016731726.

The previous prime is 21016731713. The next prime is 21016731739. The reversal of 21016731727 is 72713761012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21016731727 - 2⁷ = 21016731599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21016731767) 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, 10508365863 + 10508365864.

It is an arithmetic number, because the mean of its divisors is an integer number (10508365864).

Almost surely, 2^21016731727 is an apocalyptic number.

21016731727 is a deficient number, since it is larger than the sum of its proper divisors (1).

21016731727 is an equidigital number, since it uses as much as digits as its factorization.

21016731727 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24696, while the sum is 37.

The spelling of 21016731727 in words is "twenty-one billion, sixteen million, seven hundred thirty-one thousand, seven hundred twenty-seven".