1276805740 has 144 divisors (see below), whose sum is σ = 3329115552. Its totient is φ = 408705024.

The previous prime is 1276805687. The next prime is 1276805809. The reversal of 1276805740 is 475086721.

It is a junction number, because it is equal to n+sod(n) for n = 1276805693 and 1276805702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2881959 + ... + 2882401.

It is an arithmetic number, because the mean of its divisors is an integer number (23118858).

It is a vampire number, since it can be written as 15062 ⋅ 84770 (with its own digits).

Almost surely, 2^1276805740 is an apocalyptic number.

1276805740 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 1276805740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1664557776).

1276805740 is an abundant number, since it is smaller than the sum of its proper divisors (2052309812).

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

1276805740 is a wasteful number, since it uses less digits than its factorization.

1276805740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 647 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 40.

The square root of 1276805740 is about 35732.4186139142. The cubic root of 1276805740 is about 1084.8631114156.

The spelling of 1276805740 in words is "one billion, two hundred seventy-six million, eight hundred five thousand, seven hundred forty".