21221020210122 has 64 divisors (see below), whose sum is σ = 49210350577920. Its totient is φ = 6765821568000.

The previous prime is 21221020210121. The next prime is 21221020210129. The reversal of 21221020210122 is 22101202012212.

It is a happy number.

21221020210122 is a `hidden beast` number, since 212 + 210 + 20 + 210 + 12 + 2 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21221020210095 and 21221020210104.

It is not an unprimeable number, because it can be changed into a prime (21221020210121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28447422 + ... + 29183862.

It is an arithmetic number, because the mean of its divisors is an integer number (768911727780).

Almost surely, 2^{21221020210122} is an apocalyptic number.

21221020210122 is an abundant number, since it is smaller than the sum of its proper divisors (27989330367798).

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

21221020210122 is a wasteful number, since it uses less digits than its factorization.

21221020210122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 759676 (or 759670 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21221020210122 its reverse (22101202012212), we get a palindrome (43322222222334).

The spelling of 21221020210122 in words is "twenty-one trillion, two hundred twenty-one billion, twenty million, two hundred ten thousand, one hundred twenty-two".