217238142 has 64 divisors (see below), whose sum is σ = 495175680. Its totient is φ = 62937600.

The previous prime is 217238129. The next prime is 217238143. The reversal of 217238142 is 241832712.

It is a super-2 number, since 2×217238142² = 94384820679224328, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217238143) 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 31 ways as a sum of consecutive naturals, for example, 181498 + ... + 182690.

It is an arithmetic number, because the mean of its divisors is an integer number (7737120).

Almost surely, 2^217238142 is an apocalyptic number.

217238142 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 217238142, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247587840).

217238142 is an abundant number, since it is smaller than the sum of its proper divisors (277937538).

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

217238142 is a wasteful number, since it uses less digits than its factorization.

217238142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1329.

The product of its digits is 5376, while the sum is 30.

The square root of 217238142 is about 14739.0007123957. Note that the first 3 decimals coincide. The cubic root of 217238142 is about 601.1442442325.

The spelling of 217238142 in words is "two hundred seventeen million, two hundred thirty-eight thousand, one hundred forty-two".