121620510100 has 36 divisors (see below), whose sum is σ = 266252075964. Its totient is φ = 48217684480.

The previous prime is 121620510079. The next prime is 121620510107. The reversal of 121620510100 is 1015026121.

It can be written as a sum of positive squares in 6 ways, for example, as 57447461124 + 64173048976 = 239682^2 + 253324^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121620510107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5370139 + ... + 5392738.

It is an arithmetic number, because the mean of its divisors is an integer number (7395890999).

Almost surely, 2^121620510100 is an apocalyptic number.

121620510100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121620510100 is an abundant number, since it is smaller than the sum of its proper divisors (144631565864).

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

121620510100 is a wasteful number, since it uses less digits than its factorization.

121620510100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10763004 (or 10762997 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 19.

Adding to 121620510100 its reverse (1015026121), we get a palindrome (122635536221).

The spelling of 121620510100 in words is "one hundred twenty-one billion, six hundred twenty million, five hundred ten thousand, one hundred".