216753408 has 90 divisors (see below), whose sum is σ = 646381274. Its totient is φ = 72244224.

The previous prime is 216753401. The next prime is 216753413. The reversal of 216753408 is 804357612.

It can be written as a sum of positive squares in only one way, i.e., 215737344 + 1016064 = 14688^2 + 1008^2 .

It is a super-2 number, since 2×216753408² = 93964079759228928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216753401) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 15510 + ... + 25962.

Almost surely, 2^216753408 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 216753408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323190637).

216753408 is an abundant number, since it is smaller than the sum of its proper divisors (429627866).

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

216753408 is an equidigital number, since it uses as much as digits as its factorization.

216753408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10481 (or 10458 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 216753408 is about 14722.5476056286. The cubic root of 216753408 is about 600.6967904918.

The spelling of 216753408 in words is "two hundred sixteen million, seven hundred fifty-three thousand, four hundred eight".