1281391243200 has 252 divisors, whose sum is σ = 4557754443528. Its totient is φ = 341450188800.

The previous prime is 1281391243127. The next prime is 1281391243207. The reversal of 1281391243200 is 23421931821.

1281391243200 is a `hidden beast` number, since 1 + 2 + 8 + 1 + 391 + 243 + 20 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281391243207) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 19738795 + ... + 19803605.

Almost surely, 2^{1281391243200} is an apocalyptic number.

1281391243200 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 1281391243200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2278877221764).

1281391243200 is an abundant number, since it is smaller than the sum of its proper divisors (3276363200328).

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

1281391243200 is a wasteful number, since it uses less digits than its factorization.

1281391243200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66212 (or 66194 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 1281391243200 in words is "one trillion, two hundred eighty-one billion, three hundred ninety-one million, two hundred forty-three thousand, two hundred".