1321531200 has 588 divisors, whose sum is σ = 5370319968. Its totient is φ = 317260800.

The previous prime is 1321531157. The next prime is 1321531219. The reversal of 1321531200 is 21351231.

1321531200 is a `hidden beast` number, since 132 + 1 + 531 + 2 + 0 + 0 = 666.

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 83 ways as a sum of consecutive naturals, for example, 12830349 + ... + 12830451.

Almost surely, 2^1321531200 is an apocalyptic number.

1321531200 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 1321531200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2685159984).

1321531200 is an abundant number, since it is smaller than the sum of its proper divisors (4048788768).

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

1321531200 is a wasteful number, since it uses less digits than its factorization.

1321531200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 1321531200 is about 36352.8705881668. The cubic root of 1321531200 is about 1097.3853049576.

Adding to 1321531200 its reverse (21351231), we get a palindrome (1342882431).

The spelling of 1321531200 in words is "one billion, three hundred twenty-one million, five hundred thirty-one thousand, two hundred".