405216 has 96 divisors (see below), whose sum is σ = 1370880. Its totient is φ = 114048.

The previous prime is 405211. The next prime is 405221. The reversal of 405216 is 612504.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (405211) and next prime (405221).

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

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405211) by changing a digit.

405216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6015 + ... + 6081.

It is an arithmetic number, because the mean of its divisors is an integer number (14280).

2⁴⁰⁵²¹⁶ 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 405216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685440).

405216 is an abundant number, since it is smaller than the sum of its proper divisors (965664).

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

405216 is a wasteful number, since it uses less digits than its factorization.

405216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 405216 is about 636.5657860740. The cubic root of 405216 is about 73.9995130233. Note that the first 3 decimals are identical.

The spelling of 405216 in words is "four hundred five thousand, two hundred sixteen".