1281811896 has 96 divisors (see below), whose sum is σ = 3813264000. Its totient is φ = 387173952.

The previous prime is 1281811879. The next prime is 1281811931. The reversal of 1281811896 is 6981181821.

It is a super-2 number, since 2×1281811896² = 3286083473454229632, which contains 22 as substring.

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, 11095 + ... + 51833.

It is an arithmetic number, because the mean of its divisors is an integer number (39721500).

Almost surely, 2^1281811896 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1281811896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1906632000).

1281811896 is an abundant number, since it is smaller than the sum of its proper divisors (2531452104).

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

1281811896 is a wasteful number, since it uses less digits than its factorization.

1281811896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40793 (or 40786 counting only the distinct ones).

The product of its digits is 55296, while the sum is 45.

The square root of 1281811896 is about 35802.4007016289. The cubic root of 1281811896 is about 1086.2791220112.

The spelling of 1281811896 in words is "one billion, two hundred eighty-one million, eight hundred eleven thousand, eight hundred ninety-six".