77998973 has 4 divisors (see below), whose sum is σ = 83998908. Its totient is φ = 71999040.

The previous prime is 77998969. The next prime is 77999011. The reversal of 77998973 is 37989977.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37989977 = 2309 ⋅16453.

It can be written as a sum of positive squares in 2 ways, for example, as 24226084 + 53772889 = 4922^2 + 7333^2 .

It is a cyclic number.

It is not a de Polignac number, because 77998973 - 2² = 77998969 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 (77998273) 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, 2999948 + ... + 2999973.

It is an arithmetic number, because the mean of its divisors is an integer number (20999727).

Almost surely, 2^77998973 is an apocalyptic number.

It is an amenable number.

77998973 is a deficient number, since it is larger than the sum of its proper divisors (5999935).

77998973 is a wasteful number, since it uses less digits than its factorization.

77998973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5999934.

The product of its digits is 6001128, while the sum is 59.

The square root of 77998973 is about 8831.7027237108. The cubic root of 77998973 is about 427.2639929391.

The spelling of 77998973 in words is "seventy-seven million, nine hundred ninety-eight thousand, nine hundred seventy-three".