21213031230 has 96 divisors (see below), whose sum is σ = 58144739328. Its totient is φ = 5357822400.

The previous prime is 21213031219. The next prime is 21213031249. The reversal of 21213031230 is 3213031212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50245 + ... + 212015.

It is an arithmetic number, because the mean of its divisors is an integer number (605674368).

Almost surely, 2^21213031230 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21213031230, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29072369664).

21213031230 is an abundant number, since it is smaller than the sum of its proper divisors (36931708098).

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

21213031230 is a wasteful number, since it uses less digits than its factorization.

21213031230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161862 (or 161859 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Subtracting from 21213031230 its sum of digits (18), we obtain a palindrome (21213031212).

Adding to 21213031230 its reverse (3213031212), we get a palindrome (24426062442).

The spelling of 21213031230 in words is "twenty-one billion, two hundred thirteen million, thirty-one thousand, two hundred thirty".