1281249216 has 168 divisors, whose sum is σ = 3974128704. Its totient is φ = 392325120.

The previous prime is 1281249169. The next prime is 1281249227. The reversal of 1281249216 is 6129421821.

It is a super-2 number, since 2×1281249216² = 3283199107001229312, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2972521 + ... + 2972951.

It is an arithmetic number, because the mean of its divisors is an integer number (23655528).

Almost surely, 2^1281249216 is an apocalyptic number.

1281249216 is a gapful number since it is divisible by the number (16) 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 1281249216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1987064352).

1281249216 is an abundant number, since it is smaller than the sum of its proper divisors (2692879488).

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

1281249216 is a wasteful number, since it uses less digits than its factorization.

1281249216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859 (or 846 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1281249216 is about 35794.5417068022. The cubic root of 1281249216 is about 1086.1201499089.

The spelling of 1281249216 in words is "one billion, two hundred eighty-one million, two hundred forty-nine thousand, two hundred sixteen".