21028946727 has 4 divisors (see below), whose sum is σ = 28038595640. Its totient is φ = 14019297816.

The previous prime is 21028946681. The next prime is 21028946767. The reversal of 21028946727 is 72764982012.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21028946727 - 2⁷ = 21028946599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21028946767) 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 in 3 ways as a sum of consecutive naturals, for example, 3504824452 + ... + 3504824457.

It is an arithmetic number, because the mean of its divisors is an integer number (7009648910).

Almost surely, 2^21028946727 is an apocalyptic number.

21028946727 is a deficient number, since it is larger than the sum of its proper divisors (7009648913).

21028946727 is an equidigital number, since it uses as much as digits as its factorization.

21028946727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7009648912.

The product of its (nonzero) digits is 677376, while the sum is 48.

The spelling of 21028946727 in words is "twenty-one billion, twenty-eight million, nine hundred forty-six thousand, seven hundred twenty-seven".