216523400020 has 24 divisors (see below), whose sum is σ = 455725567584. Its totient is φ = 86413850016.

The previous prime is 216523400003. The next prime is 216523400021. The reversal of 216523400020 is 20004325612.

216523400020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216523400021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12210294 + ... + 12228013.

It is an arithmetic number, because the mean of its divisors is an integer number (18988565316).

Almost surely, 2^216523400020 is an apocalyptic number.

216523400020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216523400020 is an abundant number, since it is smaller than the sum of its proper divisors (239202167564).

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

216523400020 is a wasteful number, since it uses less digits than its factorization.

216523400020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24438759 (or 24438757 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 216523400020 its reverse (20004325612), we get a palindrome (236527725632).

The spelling of 216523400020 in words is "two hundred sixteen billion, five hundred twenty-three million, four hundred thousand, twenty".