21221210234 has 32 divisors (see below), whose sum is σ = 36525468672. Its totient is φ = 9058320000.

The previous prime is 21221210191. The next prime is 21221210237. The reversal of 21221210234 is 43201212212.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21221210237) 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 15 ways as a sum of consecutive naturals, for example, 3876119 + ... + 3881589.

It is an arithmetic number, because the mean of its divisors is an integer number (1141420896).

Almost surely, 2^21221210234 is an apocalyptic number.

21221210234 is a deficient number, since it is larger than the sum of its proper divisors (15304258438).

21221210234 is a wasteful number, since it uses less digits than its factorization.

21221210234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6542.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21221210234 its reverse (43201212212), we get a palindrome (64422422446).

The spelling of 21221210234 in words is "twenty-one billion, two hundred twenty-one million, two hundred ten thousand, two hundred thirty-four".