216509748 has 96 divisors (see below), whose sum is σ = 624691200. Its totient is φ = 56833920.

The previous prime is 216509729. The next prime is 216509749. The reversal of 216509748 is 847905612.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216509749) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 361153 + ... + 361751.

It is an arithmetic number, because the mean of its divisors is an integer number (6507200).

Almost surely, 2^216509748 is an apocalyptic number.

216509748 is a gapful number since it is divisible by the number (28) 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 216509748, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312345600).

216509748 is an abundant number, since it is smaller than the sum of its proper divisors (408181452).

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

216509748 is a wasteful number, since it uses less digits than its factorization.

216509748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 957 (or 955 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 216509748 is about 14714.2702163580. The cubic root of 216509748 is about 600.4716180857.

The spelling of 216509748 in words is "two hundred sixteen million, five hundred nine thousand, seven hundred forty-eight".