77831977 has 4 divisors (see below), whose sum is σ = 81216000. Its totient is φ = 74447956.

The previous prime is 77831959. The next prime is 77831983. The reversal of 77831977 is 77913877.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77913877 = 859 ⋅90703.

It is a cyclic number.

It is not a de Polignac number, because 77831977 - 2¹¹ = 77829929 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77831977.

It is not an unprimeable number, because it can be changed into a prime (77831987) 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, 1691977 + ... + 1692022.

It is an arithmetic number, because the mean of its divisors is an integer number (20304000).

Almost surely, 2^77831977 is an apocalyptic number.

It is an amenable number.

77831977 is a deficient number, since it is larger than the sum of its proper divisors (3384023).

77831977 is a wasteful number, since it uses less digits than its factorization.

77831977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3384022.

The product of its digits is 518616, while the sum is 49.

The square root of 77831977 is about 8822.2433088189. The cubic root of 77831977 is about 426.9588506326.

The spelling of 77831977 in words is "seventy-seven million, eight hundred thirty-one thousand, nine hundred seventy-seven".