77531138 has 8 divisors (see below), whose sum is σ = 116335740. Its totient is φ = 38752560.

The previous prime is 77531131. The next prime is 77531141. The reversal of 77531138 is 83113577.

It can be written as a sum of positive squares in 2 ways, for example, as 75986089 + 1545049 = 8717^2 + 1243^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×77531138² = 12022154719150088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 77531098 and 77531107.

It is not an unprimeable number, because it can be changed into a prime (77531131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5048 + ... + 13436.

Almost surely, 2^77531138 is an apocalyptic number.

77531138 is a deficient number, since it is larger than the sum of its proper divisors (38804602).

77531138 is a wasteful number, since it uses less digits than its factorization.

77531138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13012.

The product of its digits is 17640, while the sum is 35.

The square root of 77531138 is about 8805.1767727854. The cubic root of 77531138 is about 426.4080413717.

It can be divided in two parts, 775 and 31138, that added together give a palindrome (31913).

The spelling of 77531138 in words is "seventy-seven million, five hundred thirty-one thousand, one hundred thirty-eight".