1278253989 has 6 divisors (see below), whose sum is σ = 1846366886. Its totient is φ = 852169320.

The previous prime is 1278253981. The next prime is 1278254023. The reversal of 1278253989 is 9893528721.

1278253989 is a `hidden beast` number, since 1 + 27 + 8 + 2 + 539 + 89 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1251036900 + 27217089 = 35370^2 + 5217^2 .

It is not a de Polignac number, because 1278253989 - 2³ = 1278253981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278253981) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 71014102 + ... + 71014119.

Almost surely, 2^1278253989 is an apocalyptic number.

It is an amenable number.

1278253989 is a deficient number, since it is larger than the sum of its proper divisors (568112897).

1278253989 is a wasteful number, since it uses less digits than its factorization.

1278253989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142028227 (or 142028224 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The square root of 1278253989 is about 35752.6780675238. The cubic root of 1278253989 is about 1085.2731341783.

The spelling of 1278253989 in words is "one billion, two hundred seventy-eight million, two hundred fifty-three thousand, nine hundred eighty-nine".