77478891 has 16 divisors (see below), whose sum is σ = 118489344. Its totient is φ = 44113824.

The previous prime is 77478871. The next prime is 77478893. The reversal of 77478891 is 19887477.

It is not a de Polignac number, because 77478891 - 2¹⁵ = 77446123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77478893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 576 + ... + 12461.

It is an arithmetic number, because the mean of its divisors is an integer number (7405584).

Almost surely, 2^77478891 is an apocalyptic number.

77478891 is a deficient number, since it is larger than the sum of its proper divisors (41010453).

77478891 is a wasteful number, since it uses less digits than its factorization.

77478891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13330.

The product of its digits is 790272, while the sum is 51.

The square root of 77478891 is about 8802.2094385444. The cubic root of 77478891 is about 426.3122366505.

The spelling of 77478891 in words is "seventy-seven million, four hundred seventy-eight thousand, eight hundred ninety-one".