1212321600 has 672 divisors, whose sum is σ = 5341721600. Its totient is φ = 261273600.

The previous prime is 1212321589. The next prime is 1212321647. The reversal of 1212321600 is 61232121.

1212321600 is a `hidden beast` number, since 1 + 21 + 23 + 21 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-3 number, since 3×1212321600³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5745495 + ... + 5745705.

Almost surely, 2^1212321600 is an apocalyptic number.

1212321600 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 1212321600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2670860800).

1212321600 is an abundant number, since it is smaller than the sum of its proper divisors (4129400000).

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

1212321600 is a wasteful number, since it uses less digits than its factorization.

1212321600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1212321600 is about 34818.4089240160. The cubic root of 1212321600 is about 1066.2833171055.

Adding to 1212321600 its reverse (61232121), we get a palindrome (1273553721).

The spelling of 1212321600 in words is "one billion, two hundred twelve million, three hundred twenty-one thousand, six hundred".