21809974417 has 16 divisors (see below), whose sum is σ = 27201283200. Its totient is φ = 16988768640.

The previous prime is 21809974393. The next prime is 21809974421. The reversal of 21809974417 is 71447990812.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21809974417 - 2¹¹ = 21809972369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21809174417) 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, 175309 + ... + 272677.

It is an arithmetic number, because the mean of its divisors is an integer number (1700080200).

Almost surely, 2^21809974417 is an apocalyptic number.

It is an amenable number.

21809974417 is a deficient number, since it is larger than the sum of its proper divisors (5391308783).

21809974417 is a wasteful number, since it uses less digits than its factorization.

21809974417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100296.

The product of its (nonzero) digits is 1016064, while the sum is 52.

The spelling of 21809974417 in words is "twenty-one billion, eight hundred nine million, nine hundred seventy-four thousand, four hundred seventeen".