216825840 has 240 divisors, whose sum is σ = 908084736. Its totient is φ = 45043200.

The previous prime is 216825821. The next prime is 216825859. The reversal of 216825840 is 48528612.

It is an interprime number because it is at equal distance from previous prime (216825821) and next prime (216825859).

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 216825795 and 216825804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 53485 + ... + 57395.

Almost surely, 2^216825840 is an apocalyptic number.

216825840 is a gapful number since it is divisible by the number (20) 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 216825840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (454042368).

216825840 is an abundant number, since it is smaller than the sum of its proper divisors (691258896).

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

216825840 is a wasteful number, since it uses less digits than its factorization.

216825840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3948 (or 3939 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 216825840 is about 14725.0073005075. The cubic root of 216825840 is about 600.7636942062.

The spelling of 216825840 in words is "two hundred sixteen million, eight hundred twenty-five thousand, eight hundred forty".