1643100340 has 60 divisors (see below), whose sum is σ = 4025473956. Its totient is φ = 563332224.

The previous prime is 1643100323. The next prime is 1643100341. The reversal of 1643100340 is 430013461.

It can be written as a sum of positive squares in 2 ways, for example, as 1169776804 + 473323536 = 34202^2 + 21756^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643100341) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 30912 + ... + 65128.

Almost surely, 2^1643100340 is an apocalyptic number.

1643100340 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 1643100340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2012736978).

1643100340 is an abundant number, since it is smaller than the sum of its proper divisors (2382373616).

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

1643100340 is an equidigital number, since it uses as much as digits as its factorization.

1643100340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34254 (or 34231 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 1643100340 is about 40535.1741084209. The cubic root of 1643100340 is about 1180.0163600145.

The spelling of 1643100340 in words is "one billion, six hundred forty-three million, one hundred thousand, three hundred forty".