21453735173772 has 96 divisors (see below), whose sum is σ = 54915008698368. Its totient is φ = 6464767680000.

The previous prime is 21453735173771. The next prime is 21453735173837. The reversal of 21453735173772 is 27737153735412.

It is not an unprimeable number, because it can be changed into a prime (21453735173771) 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, 551192872 + ... + 551231792.

It is an arithmetic number, because the mean of its divisors is an integer number (572031340608).

Almost surely, 2^{21453735173772} is an apocalyptic number.

21453735173772 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21453735173772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27457504349184).

21453735173772 is an abundant number, since it is smaller than the sum of its proper divisors (33461273524596).

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

21453735173772 is a wasteful number, since it uses less digits than its factorization.

21453735173772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62191 (or 62189 counting only the distinct ones).

The product of its digits is 25930800, while the sum is 57.

The spelling of 21453735173772 in words is "twenty-one trillion, four hundred fifty-three billion, seven hundred thirty-five million, one hundred seventy-three thousand, seven hundred seventy-two".