217492240 has 80 divisors (see below), whose sum is σ = 608353920. Its totient is φ = 70640640.

The previous prime is 217492217. The next prime is 217492277. The reversal of 217492240 is 42294712.

217492240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

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, 420 + ... + 20860.

It is an arithmetic number, because the mean of its divisors is an integer number (7604424).

Almost surely, 2^217492240 is an apocalyptic number.

217492240 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 217492240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304176960).

217492240 is an abundant number, since it is smaller than the sum of its proper divisors (390861680).

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

217492240 is a wasteful number, since it uses less digits than its factorization.

217492240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20480 (or 20474 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 217492240 is about 14747.6181127665. The cubic root of 217492240 is about 601.3785340180.

The spelling of 217492240 in words is "two hundred seventeen million, four hundred ninety-two thousand, two hundred forty".