217962940 has 48 divisors (see below), whose sum is σ = 497518560. Its totient is φ = 79729920.

The previous prime is 217962937. The next prime is 217962947. The reversal of 217962940 is 49269712.

It is a junction number, because it is equal to n+sod(n) for n = 217962893 and 217962902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217962947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24495 + ... + 32185.

It is an arithmetic number, because the mean of its divisors is an integer number (10364970).

Almost surely, 2^217962940 is an apocalyptic number.

217962940 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 217962940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (248759280).

217962940 is an abundant number, since it is smaller than the sum of its proper divisors (279555620).

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

217962940 is a wasteful number, since it uses less digits than its factorization.

217962940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7822 (or 7820 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 217962940 is about 14763.5679969308. The cubic root of 217962940 is about 601.8120589318.

The spelling of 217962940 in words is "two hundred seventeen million, nine hundred sixty-two thousand, nine hundred forty".