1278011812 has 24 divisors (see below), whose sum is σ = 2788390080. Its totient is φ = 497926560.

The previous prime is 1278011809. The next prime is 1278011821. The reversal of 1278011812 is 2181108721.

It is a super-2 number, since 2×1278011812² = 3266628383223046688, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2074387 + ... + 2075002.

It is an arithmetic number, because the mean of its divisors is an integer number (116182920).

Almost surely, 2^1278011812 is an apocalyptic number.

It is an amenable number.

1278011812 is an abundant number, since it is smaller than the sum of its proper divisors (1510378268).

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

1278011812 is a wasteful number, since it uses less digits than its factorization.

1278011812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4149411 (or 4149409 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 31.

The square root of 1278011812 is about 35749.2910698940. The cubic root of 1278011812 is about 1085.2045915167.

The spelling of 1278011812 in words is "one billion, two hundred seventy-eight million, eleven thousand, eight hundred twelve".