77998131 has 6 divisors (see below), whose sum is σ = 112663980. Its totient is φ = 51998748.

The previous prime is 77998127. The next prime is 77998133. The reversal of 77998131 is 13189977.

It is not a de Polignac number, because 77998131 - 2² = 77998127 is a prime.

It is a super-2 number, since 2×77998131² = 12167416878986322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77998133) 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 5 ways as a sum of consecutive naturals, for example, 4333221 + ... + 4333238.

It is an arithmetic number, because the mean of its divisors is an integer number (18777330).

Almost surely, 2^77998131 is an apocalyptic number.

77998131 is a deficient number, since it is larger than the sum of its proper divisors (34665849).

77998131 is a wasteful number, since it uses less digits than its factorization.

77998131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8666465 (or 8666462 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The square root of 77998131 is about 8831.6550544051. The cubic root of 77998131 is about 427.2624554934.

The spelling of 77998131 in words is "seventy-seven million, nine hundred ninety-eight thousand, one hundred thirty-one".