78288977 has 4 divisors (see below), whose sum is σ = 84311220. Its totient is φ = 72266736.

The previous prime is 78288971. The next prime is 78288979. The reversal of 78288977 is 77988287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34939921 + 43349056 = 5911^2 + 6584^2 .

It is a cyclic number.

It is not a de Polignac number, because 78288977 - 2¹⁶ = 78223441 is a prime.

It is a super-2 number, since 2×78288977² = 12258327839413058, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78288971) 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 3 ways as a sum of consecutive naturals, for example, 3011102 + ... + 3011127.

It is an arithmetic number, because the mean of its divisors is an integer number (21077805).

Almost surely, 2^78288977 is an apocalyptic number.

It is an amenable number.

78288977 is a deficient number, since it is larger than the sum of its proper divisors (6022243).

78288977 is a wasteful number, since it uses less digits than its factorization.

78288977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6022242.

The product of its digits is 3161088, while the sum is 56.

The square root of 78288977 is about 8848.1058424953. The cubic root of 78288977 is about 427.7928674999.

The spelling of 78288977 in words is "seventy-eight million, two hundred eighty-eight thousand, nine hundred seventy-seven".