216540740 has 48 divisors (see below), whose sum is σ = 491203440. Its totient is φ = 79710720.

The previous prime is 216540719. The next prime is 216540769. The reversal of 216540740 is 47045612.

It can be written as a sum of positive squares in 8 ways, for example, as 3147076 + 213393664 = 1774^2 + 14608^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100070 + ... + 102210.

It is an arithmetic number, because the mean of its divisors is an integer number (10233405).

Almost surely, 2^216540740 is an apocalyptic number.

216540740 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 216540740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245601720).

216540740 is an abundant number, since it is smaller than the sum of its proper divisors (274662700).

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

216540740 is a wasteful number, since it uses less digits than its factorization.

216540740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2552 (or 2550 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 216540740 is about 14715.3233059964. The cubic root of 216540740 is about 600.5002679559.

The spelling of 216540740 in words is "two hundred sixteen million, five hundred forty thousand, seven hundred forty".