21120243210 has 64 divisors (see below), whose sum is σ = 61440716160. Its totient is φ = 5120058240.

The previous prime is 21120243197. The next prime is 21120243223. The reversal of 21120243210 is 1234202112.

It is a happy number.

21120243210 is a `hidden beast` number, since 21 + 1 + 202 + 432 + 10 = 666.

It is an interprime number because it is at equal distance from previous prime (21120243197) and next prime (21120243223).

It is a super-2 number, since 2×21120243210² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3552627 + ... + 3558566.

It is an arithmetic number, because the mean of its divisors is an integer number (960011190).

Almost surely, 2^21120243210 is an apocalyptic number.

21120243210 is an abundant number, since it is smaller than the sum of its proper divisors (40320472950).

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

21120243210 is a wasteful number, since it uses less digits than its factorization.

21120243210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7111220 (or 7111214 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21120243210 its reverse (1234202112), we get a palindrome (22354445322).

The spelling of 21120243210 in words is "twenty-one billion, one hundred twenty million, two hundred forty-three thousand, two hundred ten".