1721144340 has 72 divisors (see below), whose sum is σ = 5231110248. Its totient is φ = 458065920.

The previous prime is 1721144309. The next prime is 1721144351. The reversal of 1721144340 is 434411271.

1721144340 is a `hidden beast` number, since 1 + 7 + 211 + 443 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 18096516 + 1703047824 = 4254^2 + 41268^2 .

It is a super-2 number, since 2×1721144340² = 5924675678228071200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 84604 + ... + 102956.

It is an arithmetic number, because the mean of its divisors is an integer number (72654309).

Almost surely, 2^1721144340 is an apocalyptic number.

1721144340 is a gapful number since it is divisible by the number (10) 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 1721144340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2615555124).

1721144340 is an abundant number, since it is smaller than the sum of its proper divisors (3509965908).

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

1721144340 is a wasteful number, since it uses less digits than its factorization.

1721144340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18889 (or 18884 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 1721144340 is about 41486.6766564882. The cubic root of 1721144340 is about 1198.4109383313.

The spelling of 1721144340 in words is "one billion, seven hundred twenty-one million, one hundred forty-four thousand, three hundred forty".