1643427744 has 48 divisors (see below), whose sum is σ = 4930285248. Its totient is φ = 469550592.

The previous prime is 1643427733. The next prime is 1643427749. The reversal of 1643427744 is 4477243461.

1643427744 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1643427696 and 1643427705.

It is not an unprimeable number, because it can be changed into a prime (1643427749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1222117 + ... + 1223460.

It is an arithmetic number, because the mean of its divisors is an integer number (102714276).

Almost surely, 2^1643427744 is an apocalyptic number.

1643427744 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1643427744 is an abundant number, since it is smaller than the sum of its proper divisors (3286857504).

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

1643427744 is a wasteful number, since it uses less digits than its factorization.

1643427744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2445597 (or 2445589 counting only the distinct ones).

The product of its digits is 451584, while the sum is 42.

The square root of 1643427744 is about 40539.2124245156. The cubic root of 1643427744 is about 1180.0947314543.

The spelling of 1643427744 in words is "one billion, six hundred forty-three million, four hundred twenty-seven thousand, seven hundred forty-four".