77904538 has 4 divisors (see below), whose sum is σ = 116856810. Its totient is φ = 38952268.

The previous prime is 77904517. The next prime is 77904539. The reversal of 77904538 is 83540977.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83540977 = 13 ⋅6426229.

It can be written as a sum of positive squares in only one way, i.e., 69006249 + 8898289 = 8307^2 + 2983^2 .

It is a junction number, because it is equal to n+sod(n) for n = 77904494 and 77904503.

It is not an unprimeable number, because it can be changed into a prime (77904539) by changing a digit.

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, 19476133 + ... + 19476136.

Almost surely, 2^77904538 is an apocalyptic number.

77904538 is a deficient number, since it is larger than the sum of its proper divisors (38952272).

77904538 is a wasteful number, since it uses less digits than its factorization.

77904538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38952271.

The product of its (nonzero) digits is 211680, while the sum is 43.

The square root of 77904538 is about 8826.3547402084. The cubic root of 77904538 is about 427.0914907969.

The spelling of 77904538 in words is "seventy-seven million, nine hundred four thousand, five hundred thirty-eight".