1378129815 has 32 divisors (see below), whose sum is σ = 2451778560. Its totient is φ = 734471712.

The previous prime is 1378129813. The next prime is 1378129849. The reversal of 1378129815 is 5189218731.

It is not a de Polignac number, because 1378129815 - 2¹ = 1378129813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378129811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 246582 + ... + 252108.

It is an arithmetic number, because the mean of its divisors is an integer number (76618080).

Almost surely, 2^1378129815 is an apocalyptic number.

1378129815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1378129815 is a deficient number, since it is larger than the sum of its proper divisors (1073648745).

1378129815 is a wasteful number, since it uses less digits than its factorization.

1378129815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7388 (or 7382 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 1378129815 is about 37123.1708640305. The cubic root of 1378129815 is about 1112.8331206269.

The spelling of 1378129815 in words is "one billion, three hundred seventy-eight million, one hundred twenty-nine thousand, eight hundred fifteen".