77991445 has 16 divisors (see below), whose sum is σ = 107106048. Its totient is φ = 53406720.

The previous prime is 77991421. The next prime is 77991457. The reversal of 77991445 is 54419977.

It is not a de Polignac number, because 77991445 - 2⁷ = 77991317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77991395 and 77991404.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 41680 + ... + 43510.

It is an arithmetic number, because the mean of its divisors is an integer number (6694128).

Almost surely, 2^77991445 is an apocalyptic number.

It is an amenable number.

77991445 is a deficient number, since it is larger than the sum of its proper divisors (29114603).

77991445 is a wasteful number, since it uses less digits than its factorization.

77991445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3060.

The product of its digits is 317520, while the sum is 46.

The square root of 77991445 is about 8831.2765215455. The cubic root of 77991445 is about 427.2502468316.

The spelling of 77991445 in words is "seventy-seven million, nine hundred ninety-one thousand, four hundred forty-five".