2878378138 has 4 divisors (see below), whose sum is σ = 4317567210. Its totient is φ = 1439189068.

The previous prime is 2878378121. The next prime is 2878378163. The reversal of 2878378138 is 8318738782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8318738782 = 2 ⋅4159369391.

It can be written as a sum of positive squares in only one way, i.e., 2182104369 + 696273769 = 46713^2 + 26387^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 719594533 + ... + 719594536.

Almost surely, 2^2878378138 is an apocalyptic number.

2878378138 is a deficient number, since it is larger than the sum of its proper divisors (1439189072).

2878378138 is a wasteful number, since it uses less digits than its factorization.

2878378138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439189071.

The product of its digits is 3612672, while the sum is 55.

The square root of 2878378138 is about 53650.5185249872. The cubic root of 2878378138 is about 1422.4901980313.

The spelling of 2878378138 in words is "two billion, eight hundred seventy-eight million, three hundred seventy-eight thousand, one hundred thirty-eight".