1280191887 has 12 divisors (see below), whose sum is σ = 1991409784. Its totient is φ = 787810320.

The previous prime is 1280191879. The next prime is 1280191901. The reversal of 1280191887 is 7881910821.

It is a happy number.

It is not a de Polignac number, because 1280191887 - 2³ = 1280191879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280191837) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5470789 + ... + 5471022.

Almost surely, 2^1280191887 is an apocalyptic number.

1280191887 is a deficient number, since it is larger than the sum of its proper divisors (711217897).

1280191887 is a wasteful number, since it uses less digits than its factorization.

1280191887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10941830 (or 10941827 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 45.

The square root of 1280191887 is about 35779.7692418495. The cubic root of 1280191887 is about 1085.8213003283.

The spelling of 1280191887 in words is "one billion, two hundred eighty million, one hundred ninety-one thousand, eight hundred eighty-seven".