216415540 has 48 divisors (see below), whose sum is σ = 504221760. Its totient is φ = 77358080.

The previous prime is 216415519. The next prime is 216415547. The reversal of 216415540 is 45514612.

It is a junction number, because it is equal to n+sod(n) for n = 216415499 and 216415508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216415547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4644 + ... + 21316.

It is an arithmetic number, because the mean of its divisors is an integer number (10504620).

Almost surely, 2^216415540 is an apocalyptic number.

216415540 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 216415540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252110880).

216415540 is an abundant number, since it is smaller than the sum of its proper divisors (287806220).

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

216415540 is a wasteful number, since it uses less digits than its factorization.

216415540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16752 (or 16750 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 216415540 is about 14711.0686219595. The cubic root of 216415540 is about 600.3845127898.

The spelling of 216415540 in words is "two hundred sixteen million, four hundred fifteen thousand, five hundred forty".