216906240 has 160 divisors (see below), whose sum is σ = 706311936. Its totient is φ = 56770560.

The previous prime is 216906229. The next prime is 216906253. The reversal of 216906240 is 42609612.

It is a tau number, because it is divible by the number of its divisors (160).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 216906198 and 216906207.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 468249 + ... + 468711.

Almost surely, 2^216906240 is an apocalyptic number.

216906240 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 216906240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (353155968).

216906240 is an abundant number, since it is smaller than the sum of its proper divisors (489405696).

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

216906240 is an equidigital number, since it uses as much as digits as its factorization.

216906240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550 (or 534 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 216906240 is about 14727.7370970560. The cubic root of 216906240 is about 600.8379403264.

The spelling of 216906240 in words is "two hundred sixteen million, nine hundred six thousand, two hundred forty".