21670727727 has 16 divisors (see below), whose sum is σ = 31581584640. Its totient is φ = 13108555200.

The previous prime is 21670727681. The next prime is 21670727731. The reversal of 21670727727 is 72772707612.

It is not a de Polignac number, because 21670727727 - 2¹⁵ = 21670694959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21670727527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 613027 + ... + 647412.

It is an arithmetic number, because the mean of its divisors is an integer number (1973849040).

Almost surely, 2^21670727727 is an apocalyptic number.

21670727727 is a deficient number, since it is larger than the sum of its proper divisors (9910856913).

21670727727 is a wasteful number, since it uses less digits than its factorization.

21670727727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260974.

The product of its (nonzero) digits is 806736, while the sum is 48.

The spelling of 21670727727 in words is "twenty-one billion, six hundred seventy million, seven hundred twenty-seven thousand, seven hundred twenty-seven".