1278131402 has 8 divisors (see below), whose sum is σ = 1918217700. Its totient is φ = 638725504.

The previous prime is 1278131401. The next prime is 1278131423. The reversal of 1278131402 is 2041318721.

It can be written as a sum of positive squares in 2 ways, for example, as 1186182481 + 91948921 = 34441^2 + 9589^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1278131401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165377 + ... + 172932.

Almost surely, 2^1278131402 is an apocalyptic number.

1278131402 is a deficient number, since it is larger than the sum of its proper divisors (640086298).

1278131402 is a wasteful number, since it uses less digits than its factorization.

1278131402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340200.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 1278131402 is about 35750.9636513479. The cubic root of 1278131402 is about 1085.2384398134.

The spelling of 1278131402 in words is "one billion, two hundred seventy-eight million, one hundred thirty-one thousand, four hundred two".