77138555 has 16 divisors (see below), whose sum is σ = 99931104. Its totient is φ = 56824320.

The previous prime is 77138549. The next prime is 77138563. The reversal of 77138555 is 55583177.

It is not a de Polignac number, because 77138555 - 2⁴ = 77138539 is a prime.

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 in 15 ways as a sum of consecutive naturals, for example, 30707 + ... + 33123.

It is an arithmetic number, because the mean of its divisors is an integer number (6245694).

Almost surely, 2^77138555 is an apocalyptic number.

77138555 is a deficient number, since it is larger than the sum of its proper divisors (22792549).

77138555 is a wasteful number, since it uses less digits than its factorization.

77138555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2926.

The product of its digits is 147000, while the sum is 41.

The square root of 77138555 is about 8782.8557428663. The cubic root of 77138555 is about 425.6871099837.

It can be divided in two parts, 771 and 38555, that multiplied together give a triangular number (29725905 = T₇₇₁₀).

The spelling of 77138555 in words is "seventy-seven million, one hundred thirty-eight thousand, five hundred fifty-five".