21506663245404 has 48 divisors (see below), whose sum is σ = 50961289140608. Its totient is φ = 7057717748928.

The previous prime is 21506663245247. The next prime is 21506663245421. The reversal of 21506663245404 is 40454236660512.

It is a super-2 number, since 2×21506663245404² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6538882 + ... + 9261225.

Almost surely, 2^{21506663245404} is an apocalyptic number.

It is an amenable number.

21506663245404 is an abundant number, since it is smaller than the sum of its proper divisors (29454625895204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21506663245404 is a wasteful number, since it uses less digits than its factorization.

21506663245404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15801874 (or 15801872 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 48.

The spelling of 21506663245404 in words is "twenty-one trillion, five hundred six billion, six hundred sixty-three million, two hundred forty-five thousand, four hundred four".