21980217823 has 8 divisors (see below), whose sum is σ = 22871429568. Its totient is φ = 21106653984.

The previous prime is 21980217821. The next prime is 21980217829. The reversal of 21980217823 is 32871208912.

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 21980217823 - 2¹ = 21980217821 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21980217823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980217821) 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, 4409436 + ... + 4414417.

It is an arithmetic number, because the mean of its divisors is an integer number (2858928696).

Almost surely, 2^21980217823 is an apocalyptic number.

21980217823 is a deficient number, since it is larger than the sum of its proper divisors (891211745).

21980217823 is an equidigital number, since it uses as much as digits as its factorization.

21980217823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8823953.

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 21980217823 in words is "twenty-one billion, nine hundred eighty million, two hundred seventeen thousand, eight hundred twenty-three".