7856138 has 4 divisors (see below), whose sum is σ = 11784210. Its totient is φ = 3928068.

The previous prime is 7856089. The next prime is 7856161. The reversal of 7856138 is 8316587.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 5536609 + 2319529 = 2353^2 + 1523^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1964033 + ... + 1964036.

Almost surely, 2^7856138 is an apocalyptic number.

7856138 is a deficient number, since it is larger than the sum of its proper divisors (3928072).

7856138 is a wasteful number, since it uses less digits than its factorization.

7856138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3928071.

The product of its digits is 40320, while the sum is 38.

The square root of 7856138 is about 2802.8803042585. The cubic root of 7856138 is about 198.7938911280.

It can be divided in two parts, 7856 and 138, that multiplied together give a triangular number (1084128 = T₁₄₇₂).

The spelling of 7856138 in words is "seven million, eight hundred fifty-six thousand, one hundred thirty-eight".