1280001591 has 24 divisors (see below), whose sum is σ = 2066173200. Its totient is φ = 756835200.

The previous prime is 1280001571. The next prime is 1280001647. The reversal of 1280001591 is 1951000821.

It is not a de Polignac number, because 1280001591 - 2⁵ = 1280001559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280001551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 153616 + ... + 161733.

It is an arithmetic number, because the mean of its divisors is an integer number (86090550).

Almost surely, 2^1280001591 is an apocalyptic number.

1280001591 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1280001591 is a deficient number, since it is larger than the sum of its proper divisors (786171609).

1280001591 is a wasteful number, since it uses less digits than its factorization.

1280001591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315407 (or 315404 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 1280001591 is about 35777.1098748907. The cubic root of 1280001591 is about 1085.7674964959.

The spelling of 1280001591 in words is "one billion, two hundred eighty million, one thousand, five hundred ninety-one".