121521240400 has 120 divisors (see below), whose sum is σ = 345168443520. Its totient is φ = 40227694080.

The previous prime is 121521240353. The next prime is 121521240409. The reversal of 121521240400 is 4042125121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121521240409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 667084 + ... + 829483.

It is an arithmetic number, because the mean of its divisors is an integer number (2876403696).

Almost surely, 2^121521240400 is an apocalyptic number.

121521240400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121521240400 is an abundant number, since it is smaller than the sum of its proper divisors (223647203120).

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

121521240400 is a wasteful number, since it uses less digits than its factorization.

121521240400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1496621 (or 1496610 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 121521240400 its reverse (4042125121), we get a palindrome (125563365521).

The spelling of 121521240400 in words is "one hundred twenty-one billion, five hundred twenty-one million, two hundred forty thousand, four hundred".