1643043140 has 48 divisors (see below), whose sum is σ = 3580038000. Its totient is φ = 632658432.

The previous prime is 1643043137. The next prime is 1643043191. The reversal of 1643043140 is 413403461.

It can be written as a sum of positive squares in 8 ways, for example, as 143185156 + 1499857984 = 11966^2 + 38728^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198362 + ... + 206478.

It is an arithmetic number, because the mean of its divisors is an integer number (74584125).

Almost surely, 2^1643043140 is an apocalyptic number.

1643043140 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 1643043140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1790019000).

1643043140 is an abundant number, since it is smaller than the sum of its proper divisors (1936994860).

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

1643043140 is a wasteful number, since it uses less digits than its factorization.

1643043140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8504 (or 8502 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 1643043140 is about 40534.4685422173. The cubic root of 1643043140 is about 1180.0026668522.

The spelling of 1643043140 in words is "one billion, six hundred forty-three million, forty-three thousand, one hundred forty".