1278890001 has 24 divisors (see below), whose sum is σ = 1883909664. Its totient is φ = 835856640.

The previous prime is 1278889987. The next prime is 1278890003. The reversal of 1278890001 is 1000988721.

It is not a de Polignac number, because 1278890001 - 2⁹ = 1278889489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1278890003) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 86566 + ... + 100256.

It is an arithmetic number, because the mean of its divisors is an integer number (78496236).

Almost surely, 2^1278890001 is an apocalyptic number.

It is an amenable number.

1278890001 is a deficient number, since it is larger than the sum of its proper divisors (605019663).

1278890001 is a wasteful number, since it uses less digits than its factorization.

1278890001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13901 (or 13898 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 1278890001 is about 35761.5715678156. The cubic root of 1278890001 is about 1085.4531016166.

The spelling of 1278890001 in words is "one billion, two hundred seventy-eight million, eight hundred ninety thousand, one".