20121022100 has 36 divisors (see below), whose sum is σ = 44153228700. Its totient is φ = 7957973760.

The previous prime is 20121022079. The next prime is 20121022111. The reversal of 20121022100 is 122012102.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1971004816 + 18150017284 = 44396^2 + 134722^2 .

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1121495 + ... + 1139294.

It is an arithmetic number, because the mean of its divisors is an integer number (1226478575).

Almost surely, 2^20121022100 is an apocalyptic number.

20121022100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121022100 is an abundant number, since it is smaller than the sum of its proper divisors (24032206600).

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

20121022100 is a wasteful number, since it uses less digits than its factorization.

20121022100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2260892 (or 2260885 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20121022100 its reverse (122012102), we get a palindrome (20243034202).

The spelling of 20121022100 in words is "twenty billion, one hundred twenty-one million, twenty-two thousand, one hundred".