21173518293312 has 448 divisors, whose sum is σ = 73721859932160. Its totient is φ = 5195939788800.

The previous prime is 21173518293227. The next prime is 21173518293349. The reversal of 21173518293312 is 21339281537112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 102986137 + ... + 103191527.

Almost surely, 2^{21173518293312} is an apocalyptic number.

21173518293312 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 21173518293312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36860929966080).

21173518293312 is an abundant number, since it is smaller than the sum of its proper divisors (52548341638848).

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

21173518293312 is a wasteful number, since it uses less digits than its factorization.

21173518293312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205810 (or 205800 counting only the distinct ones).

The product of its digits is 544320, while the sum is 48.

The spelling of 21173518293312 in words is "twenty-one trillion, one hundred seventy-three billion, five hundred eighteen million, two hundred ninety-three thousand, three hundred twelve".