78877771 has 4 divisors (see below), whose sum is σ = 90146032. Its totient is φ = 67609512.

The previous prime is 78877699. The next prime is 78877801. The reversal of 78877771 is 17777887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17777887 = 41 ⋅433607.

It is a cyclic number.

It is not a de Polignac number, because 78877771 - 2¹⁷ = 78746699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78877871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5634120 + ... + 5634133.

It is an arithmetic number, because the mean of its divisors is an integer number (22536508).

Almost surely, 2^78877771 is an apocalyptic number.

78877771 is a deficient number, since it is larger than the sum of its proper divisors (11268261).

78877771 is a wasteful number, since it uses less digits than its factorization.

78877771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11268260.

The product of its digits is 1075648, while the sum is 52.

The square root of 78877771 is about 8881.3158371944. The cubic root of 78877771 is about 428.8626351702.

The spelling of 78877771 in words is "seventy-eight million, eight hundred seventy-seven thousand, seven hundred seventy-one".