6721081840158 has 128 divisors (see below), whose sum is σ = 16814522695680. Its totient is φ = 1747703381760.

The previous prime is 6721081840141. The next prime is 6721081840159. The reversal of 6721081840158 is 8510481801276.

It is a super-2 number, since 2×6721081840158² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6721081840158.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721081840159) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2397535 + ... + 4380677.

It is an arithmetic number, because the mean of its divisors is an integer number (131363458560).

Almost surely, 2^{6721081840158} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6721081840158, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8407261347840).

6721081840158 is an abundant number, since it is smaller than the sum of its proper divisors (10093440855522).

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

6721081840158 is a wasteful number, since it uses less digits than its factorization.

6721081840158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983342.

The product of its (nonzero) digits is 860160, while the sum is 51.

The spelling of 6721081840158 in words is "six trillion, seven hundred twenty-one billion, eighty-one million, eight hundred forty thousand, one hundred fifty-eight".