1643269240 has 128 divisors (see below), whose sum is σ = 3897875520. Its totient is φ = 623001600.

The previous prime is 1643269223. The next prime is 1643269267. The reversal of 1643269240 is 429623461.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1643269240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12543975 + ... + 12544105.

Almost surely, 2^1643269240 is an apocalyptic number.

1643269240 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 1643269240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1948937760).

1643269240 is an abundant number, since it is smaller than the sum of its proper divisors (2254606280).

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

1643269240 is a wasteful number, since it uses less digits than its factorization.

1643269240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 37.

The square root of 1643269240 is about 40537.2574306649. The cubic root of 1643269240 is about 1180.0567912914.

The spelling of 1643269240 in words is "one billion, six hundred forty-three million, two hundred sixty-nine thousand, two hundred forty".