77989823 has 4 divisors (see below), whose sum is σ = 78420888. Its totient is φ = 77558760.

The previous prime is 77989819. The next prime is 77989837. The reversal of 77989823 is 32898977.

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 77989823 - 2² = 77989819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77989883) 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, 215261 + ... + 215622.

It is an arithmetic number, because the mean of its divisors is an integer number (19605222).

Almost surely, 2^77989823 is an apocalyptic number.

77989823 is a deficient number, since it is larger than the sum of its proper divisors (431065).

77989823 is a wasteful number, since it uses less digits than its factorization.

77989823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431064.

The product of its digits is 1524096, while the sum is 53.

The square root of 77989823 is about 8831.1846883643. The cubic root of 77989823 is about 427.2472849481.

The spelling of 77989823 in words is "seventy-seven million, nine hundred eighty-nine thousand, eight hundred twenty-three".