121121210100100 has 144 divisors (see below), whose sum is σ = 307723022966016. Its totient is φ = 40512296448000.

The previous prime is 121121210100073. The next prime is 121121210100103. The reversal of 121121210100100 is 1001012121121.

It is a happy number.

It is a super-2 number, since 2×121121210100100² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121121210100103) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 608082124 + ... + 608281276.

It is an arithmetic number, because the mean of its divisors is an integer number (2136965437264).

Almost surely, 2^{121121210100100} is an apocalyptic number.

121121210100100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121121210100100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153861511483008).

121121210100100 is an abundant number, since it is smaller than the sum of its proper divisors (186601812865916).

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

121121210100100 is a wasteful number, since it uses less digits than its factorization.

121121210100100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220406 (or 220399 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 121121210100100 its reverse (1001012121121), we get a palindrome (122122222221221).

The spelling of 121121210100100 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, two hundred ten million, one hundred thousand, one hundred".