121221034400 has 72 divisors (see below), whose sum is σ = 297433423980. Its totient is φ = 48242216960.

The previous prime is 121221034399. The next prime is 121221034409. The reversal of 121221034400 is 4430122121.

It can be written as a sum of positive squares in 6 ways, for example, as 74749747216 + 46471287184 = 273404^2 + 215572^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (121221034409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 226985 + ... + 542184.

Almost surely, 2^121221034400 is an apocalyptic number.

121221034400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121221034400 is an abundant number, since it is smaller than the sum of its proper divisors (176212389580).

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

121221034400 is a wasteful number, since it uses less digits than its factorization.

121221034400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769386 (or 769373 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 121221034400 its reverse (4430122121), we get a palindrome (125651156521).

The spelling of 121221034400 in words is "one hundred twenty-one billion, two hundred twenty-one million, thirty-four thousand, four hundred".