1277520640 has 144 divisors (see below), whose sum is σ = 3421214496. Its totient is φ = 453017600.

The previous prime is 1277520631. The next prime is 1277520661. The reversal of 1277520640 is 460257721.

It is a junction number, because it is equal to n+sod(n) for n = 1277520596 and 1277520605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 576174 + ... + 578386.

It is an arithmetic number, because the mean of its divisors is an integer number (23758434).

Almost surely, 2^1277520640 is an apocalyptic number.

1277520640 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 1277520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1710607248).

1277520640 is an abundant number, since it is smaller than the sum of its proper divisors (2143693856).

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

1277520640 is a wasteful number, since it uses less digits than its factorization.

1277520640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2286 (or 2272 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 34.

The square root of 1277520640 is about 35742.4207350314. The cubic root of 1277520640 is about 1085.0655499200.

The spelling of 1277520640 in words is "one billion, two hundred seventy-seven million, five hundred twenty thousand, six hundred forty".