21873638445 has 16 divisors (see below), whose sum is σ = 35095317120. Its totient is φ = 11633441984.

The previous prime is 21873638417. The next prime is 21873638447. The reversal of 21873638445 is 54483637812.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21873638445 - 2⁷ = 21873638317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21873638447) 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, 2025594 + ... + 2036363.

It is an arithmetic number, because the mean of its divisors is an integer number (2193457320).

Almost surely, 2^21873638445 is an apocalyptic number.

It is an amenable number.

21873638445 is a deficient number, since it is larger than the sum of its proper divisors (13221678675).

21873638445 is a wasteful number, since it uses less digits than its factorization.

21873638445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4062324.

The product of its digits is 3870720, while the sum is 51.

The spelling of 21873638445 in words is "twenty-one billion, eight hundred seventy-three million, six hundred thirty-eight thousand, four hundred forty-five".