20120102100021 has 32 divisors (see below), whose sum is σ = 34900594956288. Its totient is φ = 9997566258240.

The previous prime is 20120102099987. The next prime is 20120102100029. The reversal of 20120102100021 is 12000120102102.

It is not a de Polignac number, because 20120102100021 - 2¹⁹ = 20120101575733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20120102100029) 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, 1893473146 + ... + 1893483771.

It is an arithmetic number, because the mean of its divisors is an integer number (1090643592384).

Almost surely, 2^{20120102100021} is an apocalyptic number.

20120102100021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20120102100021 is a deficient number, since it is larger than the sum of its proper divisors (14780492856267).

20120102100021 is a wasteful number, since it uses less digits than its factorization.

20120102100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3786956961.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20120102100021 its reverse (12000120102102), we get a palindrome (32120222202123).

The spelling of 20120102100021 in words is "twenty trillion, one hundred twenty billion, one hundred two million, one hundred thousand, twenty-one".