21755212200 has 96 divisors (see below), whose sum is σ = 74934638400. Its totient is φ = 5801388480.

The previous prime is 21755212187. The next prime is 21755212201. The reversal of 21755212200 is 221255712.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21755212201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2008972 + ... + 2019771.

It is an arithmetic number, because the mean of its divisors is an integer number (780569150).

Almost surely, 2^21755212200 is an apocalyptic number.

21755212200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21755212200 is an abundant number, since it is smaller than the sum of its proper divisors (53179426200).

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

21755212200 is a wasteful number, since it uses less digits than its factorization.

21755212200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4028768 (or 4028753 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

Adding to 21755212200 its reverse (221255712), we get a palindrome (21976467912).

The spelling of 21755212200 in words is "twenty-one billion, seven hundred fifty-five million, two hundred twelve thousand, two hundred".