643416 has 64 divisors (see below), whose sum is σ = 1814400. Its totient is φ = 188928.

The previous prime is 643403. The next prime is 643421. The reversal of 643416 is 614346.

643416 = T₂₁ + T₂₂ + ... + T₁₅₆.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a nialpdrome in base 15.

It is a congruent number.

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, 7711 + ... + 7793.

It is an arithmetic number, because the mean of its divisors is an integer number (28350).

2⁶⁴³⁴¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907200).

643416 is an abundant number, since it is smaller than the sum of its proper divisors (1170984).

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

643416 is a wasteful number, since it uses less digits than its factorization.

643416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 124 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

The square root of 643416 is about 802.1321586871. The cubic root of 643416 is about 86.3304395539.

The spelling of 643416 in words is "six hundred forty-three thousand, four hundred sixteen".