1278786215 has 16 divisors (see below), whose sum is σ = 1760444928. Its totient is φ = 873541536.

The previous prime is 1278786191. The next prime is 1278786217. The reversal of 1278786215 is 5126878721.

It is not a de Polignac number, because 1278786215 - 2¹⁶ = 1278720679 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1278786215.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278786217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60257 + ... + 78666.

It is an arithmetic number, because the mean of its divisors is an integer number (110027808).

Almost surely, 2^1278786215 is an apocalyptic number.

1278786215 is a deficient number, since it is larger than the sum of its proper divisors (481658713).

1278786215 is a wasteful number, since it uses less digits than its factorization.

1278786215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139198.

The product of its digits is 376320, while the sum is 47.

The square root of 1278786215 is about 35760.1204556137. The cubic root of 1278786215 is about 1085.4237381626.

The spelling of 1278786215 in words is "one billion, two hundred seventy-eight million, seven hundred eighty-six thousand, two hundred fifteen".