2121350400 has 324 divisors, whose sum is σ = 8170597708. Its totient is φ = 521994240.

The previous prime is 2121350383. The next prime is 2121350401. The reversal of 2121350400 is 40531212.

2121350400 is a `hidden beast` number, since 2 + 1 + 213 + 50 + 400 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 308634624 + 1812715776 = 17568^2 + 42576^2 .

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 (2121350401) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 747384 + ... + 750216.

Almost surely, 2^2121350400 is an apocalyptic number.

2121350400 is a gapful number since it is divisible by the number (20) 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 2121350400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4085298854).

2121350400 is an abundant number, since it is smaller than the sum of its proper divisors (6049247308).

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

2121350400 is a wasteful number, since it uses less digits than its factorization.

2121350400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2878 (or 2856 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 2121350400 is about 46058.1198053069. The cubic root of 2121350400 is about 1284.9043618607.

Adding to 2121350400 its reverse (40531212), we get a palindrome (2161881612).

The spelling of 2121350400 in words is "two billion, one hundred twenty-one million, three hundred fifty thousand, four hundred".