121521010104 has 480 divisors, whose sum is σ = 401493652560. Its totient is φ = 34017822720.

The previous prime is 121521010057. The next prime is 121521010109. The reversal of 121521010104 is 401010125121.

121521010104 is a `hidden beast` number, since 121 + 521 + 0 + 10 + 10 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121521010109) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 137622447 + ... + 137623329.

Almost surely, 2^121521010104 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121521010104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200746826280).

121521010104 is an abundant number, since it is smaller than the sum of its proper divisors (279972642456).

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

121521010104 is a wasteful number, since it uses less digits than its factorization.

121521010104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993 (or 949 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

Adding to 121521010104 its reverse (401010125121), we get a palindrome (522531135225).

The spelling of 121521010104 in words is "one hundred twenty-one billion, five hundred twenty-one million, ten thousand, one hundred four".