1643231616 has 96 divisors (see below), whose sum is σ = 4726604520. Its totient is φ = 505589760.

The previous prime is 1643231609. The next prime is 1643231617. The reversal of 1643231616 is 6161323461.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643231617) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52236 + ... + 77556.

Almost surely, 2^1643231616 is an apocalyptic number.

1643231616 is a gapful number since it is divisible by the number (16) 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 1643231616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2363302260).

1643231616 is an abundant number, since it is smaller than the sum of its proper divisors (3083372904).

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

1643231616 is a wasteful number, since it uses less digits than its factorization.

1643231616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25364 (or 25339 counting only the distinct ones).

The product of its digits is 15552, while the sum is 33.

The square root of 1643231616 is about 40536.7933610936. The cubic root of 1643231616 is about 1180.0477850993.

The spelling of 1643231616 in words is "one billion, six hundred forty-three million, two hundred thirty-one thousand, six hundred sixteen".