21231231210 has 96 divisors (see below), whose sum is σ = 63711902592. Its totient is φ = 4804790400.

The previous prime is 21231231193. The next prime is 21231231211. The reversal of 21231231210 is 1213213212.

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

It is not an unprimeable number, because it can be changed into a prime (21231231211) 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 47 ways as a sum of consecutive naturals, for example, 103204 + ... + 230463.

It is an arithmetic number, because the mean of its divisors is an integer number (663665652).

Almost surely, 2^21231231210 is an apocalyptic number.

21231231210 is an abundant number, since it is smaller than the sum of its proper divisors (42480671382).

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

21231231210 is a wasteful number, since it uses less digits than its factorization.

21231231210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333788 (or 333785 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21231231210 its reverse (1213213212), we get a palindrome (22444444422).

The spelling of 21231231210 in words is "twenty-one billion, two hundred thirty-one million, two hundred thirty-one thousand, two hundred ten".