21180579829 has 4 divisors (see below), whose sum is σ = 21189591360. Its totient is φ = 21171568300.

The previous prime is 21180579757. The next prime is 21180579851. The reversal of 21180579829 is 92897508112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21180579829 - 2²⁷ = 21046362101 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 (21180577829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4502239 + ... + 4506940.

It is an arithmetic number, because the mean of its divisors is an integer number (5297397840).

Almost surely, 2^21180579829 is an apocalyptic number.

It is an amenable number.

21180579829 is a deficient number, since it is larger than the sum of its proper divisors (9011531).

21180579829 is an equidigital number, since it uses as much as digits as its factorization.

21180579829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9011530.

The product of its (nonzero) digits is 725760, while the sum is 52.

The spelling of 21180579829 in words is "twenty-one billion, one hundred eighty million, five hundred seventy-nine thousand, eight hundred twenty-nine".