217012540 has 24 divisors (see below), whose sum is σ = 458791200. Its totient is φ = 86221248.

The previous prime is 217012517. The next prime is 217012541. The reversal of 217012540 is 45210712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217012541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33432 + ... + 39391.

It is an arithmetic number, because the mean of its divisors is an integer number (19116300).

Almost surely, 2^217012540 is an apocalyptic number.

217012540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217012540 is an abundant number, since it is smaller than the sum of its proper divisors (241778660).

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

217012540 is a wasteful number, since it uses less digits than its factorization.

217012540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72981 (or 72979 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 217012540 is about 14731.3454918415. The cubic root of 217012540 is about 600.9360758808.

The spelling of 217012540 in words is "two hundred seventeen million, twelve thousand, five hundred forty".