1281211200 has 252 divisors, whose sum is σ = 4587250668. Its totient is φ = 339148800.

The previous prime is 1281211193. The next prime is 1281211219. The reversal of 1281211200 is 21121821.

It can be written as a sum of positive squares in 6 ways, for example, as 166719744 + 1114491456 = 12912^2 + 33384^2 .

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 35 ways as a sum of consecutive naturals, for example, 2778970 + ... + 2779430.

Almost surely, 2^1281211200 is an apocalyptic number.

1281211200 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 1281211200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2293625334).

1281211200 is an abundant number, since it is smaller than the sum of its proper divisors (3306039468).

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

1281211200 is a wasteful number, since it uses less digits than its factorization.

1281211200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682 (or 664 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 1281211200 is about 35794.0106721781. The cubic root of 1281211200 is about 1086.1094076969.

The spelling of 1281211200 in words is "one billion, two hundred eighty-one million, two hundred eleven thousand, two hundred".