1278870640 has 40 divisors (see below), whose sum is σ = 3009213648. Its totient is φ = 505382400.

The previous prime is 1278870631. The next prime is 1278870641. The reversal of 1278870640 is 460788721.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×1278870640² = 3271020227708019200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278870641) 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 7 ways as a sum of consecutive naturals, for example, 89661 + ... + 102940.

Almost surely, 2^1278870640 is an apocalyptic number.

1278870640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1278870640 is an abundant number, since it is smaller than the sum of its proper divisors (1730343008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1278870640 is a wasteful number, since it uses less digits than its factorization.

1278870640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192697 (or 192691 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 43.

The square root of 1278870640 is about 35761.3008711932. The cubic root of 1278870640 is about 1085.4476240636.

The spelling of 1278870640 in words is "one billion, two hundred seventy-eight million, eight hundred seventy thousand, six hundred forty".