21823131991548 has 96 divisors (see below), whose sum is σ = 55492213996800. Its totient is φ = 6648688134144.

The previous prime is 21823131991547. The next prime is 21823131991579. The reversal of 21823131991548 is 84519913132812.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21823131991547) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7196940 + ... + 9769452.

It is an arithmetic number, because the mean of its divisors is an integer number (578043895800).

Almost surely, 2^{21823131991548} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21823131991548, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27746106998400).

21823131991548 is an abundant number, since it is smaller than the sum of its proper divisors (33669082005252).

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

21823131991548 is a wasteful number, since it uses less digits than its factorization.

21823131991548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2573851 (or 2573849 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 57.

The spelling of 21823131991548 in words is "twenty-one trillion, eight hundred twenty-three billion, one hundred thirty-one million, nine hundred ninety-one thousand, five hundred forty-eight".