20100121210100 has 36 divisors (see below), whose sum is σ = 43617723497964. Its totient is φ = 8039963604480.

The previous prime is 20100121210079. The next prime is 20100121210121. The reversal of 20100121210100 is 101212100102.

It is an interprime number because it is at equal distance from previous prime (20100121210079) and next prime (20100121210121).

It can be written as a sum of positive squares in 6 ways, for example, as 190355944804 + 19909765265296 = 436298^2 + 4462036^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8926394 + ... + 10949006.

It is an arithmetic number, because the mean of its divisors is an integer number (1211603430499).

Almost surely, 2^{20100121210100} is an apocalyptic number.

20100121210100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20100121210100 is an abundant number, since it is smaller than the sum of its proper divisors (23517602287864).

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

20100121210100 is a wasteful number, since it uses less digits than its factorization.

20100121210100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122004 (or 2121997 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20100121210100 its reverse (101212100102), we get a palindrome (20201333310202).

The spelling of 20100121210100 in words is "twenty trillion, one hundred billion, one hundred twenty-one million, two hundred ten thousand, one hundred".