21607421211 has 12 divisors (see below), whose sum is σ = 31438536792. Its totient is φ = 14299801056.

The previous prime is 21607421207. The next prime is 21607421309. The reversal of 21607421211 is 11212470612.

21607421211 is a `hidden beast` number, since 2 + 1 + 607 + 42 + 1 + 2 + 11 = 666.

It is not a de Polignac number, because 21607421211 - 2² = 21607421207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21607428211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8760901 + ... + 8763366.

It is an arithmetic number, because the mean of its divisors is an integer number (2619878066).

Almost surely, 2^21607421211 is an apocalyptic number.

21607421211 is a deficient number, since it is larger than the sum of its proper divisors (9831115581).

21607421211 is a wasteful number, since it uses less digits than its factorization.

21607421211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17524410 (or 17524407 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

Adding to 21607421211 its reverse (11212470612), we get a palindrome (32819891823).

The spelling of 21607421211 in words is "twenty-one billion, six hundred seven million, four hundred twenty-one thousand, two hundred eleven".