12121211312400 has 120 divisors (see below), whose sum is σ = 38842708818240. Its totient is φ = 3231121886720.

The previous prime is 12121211312377. The next prime is 12121211312401. The reversal of 12121211312400 is 421311212121.

It is a tau number, because it is divible by the number of its divisors (120).

It is not an unprimeable number, because it can be changed into a prime (12121211312401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1356181 + ... + 5107019.

It is an arithmetic number, because the mean of its divisors is an integer number (323689240152).

Almost surely, 2^{12121211312400} is an apocalyptic number.

12121211312400 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 12121211312400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19421354409120).

12121211312400 is an abundant number, since it is smaller than the sum of its proper divisors (26721497505840).

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

12121211312400 is a wasteful number, since it uses less digits than its factorization.

12121211312400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3753553 (or 3753542 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 21.

Adding to 12121211312400 its reverse (421311212121), we get a palindrome (12542522524521).

The spelling of 12121211312400 in words is "twelve trillion, one hundred twenty-one billion, two hundred eleven million, three hundred twelve thousand, four hundred".