21576116821 has 8 divisors (see below), whose sum is σ = 24752179584. Its totient is φ = 18423494160.

The previous prime is 21576116747. The next prime is 21576116827. The reversal of 21576116821 is 12861167512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21576116821 - 2²¹ = 21574019669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21576116827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5858050 + ... + 5861731.

It is an arithmetic number, because the mean of its divisors is an integer number (3094022448).

Almost surely, 2^21576116821 is an apocalyptic number.

It is an amenable number.

21576116821 is a deficient number, since it is larger than the sum of its proper divisors (3176062763).

21576116821 is a wasteful number, since it uses less digits than its factorization.

21576116821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11720051.

The product of its digits is 40320, while the sum is 40.

The spelling of 21576116821 in words is "twenty-one billion, five hundred seventy-six million, one hundred sixteen thousand, eight hundred twenty-one".