21212323030 has 32 divisors (see below), whose sum is σ = 39199694688. Its totient is φ = 8261260800.

The previous prime is 21212323009. The next prime is 21212323037. The reversal of 21212323030 is 3032321212.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21212322989 and 21212323007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212323037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83331 + ... + 222190.

It is an arithmetic number, because the mean of its divisors is an integer number (1224990459).

Almost surely, 2^21212323030 is an apocalyptic number.

21212323030 is a deficient number, since it is larger than the sum of its proper divisors (17987371658).

21212323030 is a wasteful number, since it uses less digits than its factorization.

21212323030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305712.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21212323030 its reverse (3032321212), we get a palindrome (24244644242).

The spelling of 21212323030 in words is "twenty-one billion, two hundred twelve million, three hundred twenty-three thousand, thirty".