21106026405 has 48 divisors (see below), whose sum is σ = 40774518720. Its totient is φ = 10036790784.

The previous prime is 21106026401. The next prime is 21106026407. The reversal of 21106026405 is 50462060112.

21106026405 is a `hidden beast` number, since 2 + 1 + 10 + 6 + 0 + 2 + 640 + 5 = 666.

It is not a de Polignac number, because 21106026405 - 2² = 21106026401 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21106026401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 711507 + ... + 740576.

It is an arithmetic number, because the mean of its divisors is an integer number (849469140).

Almost surely, 2^21106026405 is an apocalyptic number.

It is an amenable number.

21106026405 is a deficient number, since it is larger than the sum of its proper divisors (19668492315).

21106026405 is a wasteful number, since it uses less digits than its factorization.

21106026405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1452130 (or 1452127 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 21106026405 its reverse (50462060112), we get a palindrome (71568086517).

The spelling of 21106026405 in words is "twenty-one billion, one hundred six million, twenty-six thousand, four hundred five".