1212420400 has 120 divisors (see below), whose sum is σ = 3172453200. Its totient is φ = 443520000.

The previous prime is 1212420379. The next prime is 1212420401. The reversal of 1212420400 is 40242121.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (1212420401) 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, 217650 + ... + 223150.

It is an arithmetic number, because the mean of its divisors is an integer number (26437110).

Almost surely, 2^1212420400 is an apocalyptic number.

1212420400 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 1212420400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1586226600).

1212420400 is an abundant number, since it is smaller than the sum of its proper divisors (1960032800).

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

1212420400 is a wasteful number, since it uses less digits than its factorization.

1212420400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5567 (or 5556 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 1212420400 is about 34819.8276848120. The cubic root of 1212420400 is about 1066.3122824477.

Adding to 1212420400 its reverse (40242121), we get a palindrome (1252662521).

The spelling of 1212420400 in words is "one billion, two hundred twelve million, four hundred twenty thousand, four hundred".