1321249800 has 192 divisors, whose sum is σ = 4435966080. Its totient is φ = 323389440.

The previous prime is 1321249771. The next prime is 1321249807. The reversal of 1321249800 is 89421231.

It is a Cunningham number, because it is equal to 36349²-1.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (1321249807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1817037 + ... + 1817763.

It is an arithmetic number, because the mean of its divisors is an integer number (23103990).

Almost surely, 2^1321249800 is an apocalyptic number.

1321249800 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 1321249800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2217983040).

1321249800 is an abundant number, since it is smaller than the sum of its proper divisors (3114716280).

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

1321249800 is a wasteful number, since it uses less digits than its factorization.

1321249800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992 (or 983 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1321249800 is about 36348.9999862445. Note that the first 4 decimals coincide. The cubic root of 1321249800 is about 1097.3074089166.

The spelling of 1321249800 in words is "one billion, three hundred twenty-one million, two hundred forty-nine thousand, eight hundred".