213721825681728 has 1344 divisors, whose sum is σ = 782622436377600. Its totient is φ = 55402117005312.

The previous prime is 213721825681709. The next prime is 213721825681729. The reversal of 213721825681728 is 827186528127312.

It is a happy number.

213721825681728 is a `hidden beast` number, since 2 + 1 + 37 + 2 + 1 + 8 + 2 + 568 + 17 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213721825681729) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 36242463676 + ... + 36242469572.

It is an arithmetic number, because the mean of its divisors is an integer number (582308360400).

Almost surely, 2^{213721825681728} is an apocalyptic number.

213721825681728 is a gapful number since it is divisible by the number (28) 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 213721825681728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391311218188800).

213721825681728 is an abundant number, since it is smaller than the sum of its proper divisors (568900610695872).

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

213721825681728 is a wasteful number, since it uses less digits than its factorization.

213721825681728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6189 (or 6162 counting only the distinct ones).

The product of its digits is 36126720, while the sum is 63.

The spelling of 213721825681728 in words is "two hundred thirteen trillion, seven hundred twenty-one billion, eight hundred twenty-five million, six hundred eighty-one thousand, seven hundred twenty-eight".