1721611543722 has 128 divisors (see below), whose sum is σ = 4185518469120. Its totient is φ = 461586565440.

The previous prime is 1721611543703. The next prime is 1721611543727. The reversal of 1721611543722 is 2273451161271.

It is a super-2 number, since 2×1721611543722² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (1721611543727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 143809197 + ... + 143821167.

It is an arithmetic number, because the mean of its divisors is an integer number (32699363040).

Almost surely, 2^{1721611543722} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1721611543722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2092759234560).

1721611543722 is an abundant number, since it is smaller than the sum of its proper divisors (2463906925398).

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

1721611543722 is an equidigital number, since it uses as much as digits as its factorization.

1721611543722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12165 (or 12059 counting only the distinct ones).

The product of its digits is 141120, while the sum is 42.

The spelling of 1721611543722 in words is "one trillion, seven hundred twenty-one billion, six hundred eleven million, five hundred forty-three thousand, seven hundred twenty-two".