21161020727 has 16 divisors (see below), whose sum is σ = 27771129600. Its totient is φ = 15621258240.

The previous prime is 21161020711. The next prime is 21161020729. The reversal of 21161020727 is 72702016112.

It is not a de Polignac number, because 21161020727 - 2⁴ = 21161020711 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21161020727.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161020729) 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, 7230602 + ... + 7233527.

It is an arithmetic number, because the mean of its divisors is an integer number (1735695600).

Almost surely, 2^21161020727 is an apocalyptic number.

21161020727 is a deficient number, since it is larger than the sum of its proper divisors (6610108873).

21161020727 is a wasteful number, since it uses less digits than its factorization.

21161020727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14464166.

The product of its (nonzero) digits is 2352, while the sum is 29.

Adding to 21161020727 its reverse (72702016112), we get a palindrome (93863036839).

The spelling of 21161020727 in words is "twenty-one billion, one hundred sixty-one million, twenty thousand, seven hundred twenty-seven".