216999520 has 24 divisors (see below), whose sum is σ = 512661744. Its totient is φ = 86799744.

The previous prime is 216999481. The next prime is 216999527. The reversal of 216999520 is 25999612.

It is a happy number.

216999520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216999527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 677964 + ... + 678283.

It is an arithmetic number, because the mean of its divisors is an integer number (21360906).

Almost surely, 2^216999520 is an apocalyptic number.

216999520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216999520 is an abundant number, since it is smaller than the sum of its proper divisors (295662224).

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

216999520 is a wasteful number, since it uses less digits than its factorization.

216999520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1356262 (or 1356254 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 216999520 is about 14730.9035703856. The cubic root of 216999520 is about 600.9240576134.

The spelling of 216999520 in words is "two hundred sixteen million, nine hundred ninety-nine thousand, five hundred twenty".