21112505405 has 32 divisors (see below), whose sum is σ = 27064074240. Its totient is φ = 15764742720.

The previous prime is 21112505369. The next prime is 21112505417. The reversal of 21112505405 is 50450521112.

It is not a de Polignac number, because 21112505405 - 2²⁸ = 20844069949 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3016460 + ... + 3023450.

It is an arithmetic number, because the mean of its divisors is an integer number (845752320).

Almost surely, 2^21112505405 is an apocalyptic number.

It is an amenable number.

21112505405 is a deficient number, since it is larger than the sum of its proper divisors (5951568835).

21112505405 is a wasteful number, since it uses less digits than its factorization.

21112505405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7481.

The product of its (nonzero) digits is 2000, while the sum is 26.

The spelling of 21112505405 in words is "twenty-one billion, one hundred twelve million, five hundred five thousand, four hundred five".