77988399 has 4 divisors (see below), whose sum is σ = 103984536. Its totient is φ = 51992264.

The previous prime is 77988397. The next prime is 77988413. The reversal of 77988399 is 99388977.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 77988399 - 2¹ = 77988397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77988397) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 12998064 + ... + 12998069.

It is an arithmetic number, because the mean of its divisors is an integer number (25996134).

Almost surely, 2^77988399 is an apocalyptic number.

77988399 is a deficient number, since it is larger than the sum of its proper divisors (25996137).

77988399 is a wasteful number, since it uses less digits than its factorization.

77988399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25996136.

The product of its digits is 6858432, while the sum is 60.

The square root of 77988399 is about 8831.1040646116. The cubic root of 77988399 is about 427.2446845925.

It can be divided in two parts, 77988 and 399, that added together give a palindrome (78387).

The spelling of 77988399 in words is "seventy-seven million, nine hundred eighty-eight thousand, three hundred ninety-nine".