87477778 has 4 divisors (see below), whose sum is σ = 131216670. Its totient is φ = 43738888.

The previous prime is 87477757. The next prime is 87477779. The reversal of 87477778 is 87777478.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87777478 = 2 ⋅43888739.

It can be written as a sum of positive squares in only one way, i.e., 65076489 + 22401289 = 8067^2 + 4733^2 .

It is not an unprimeable number, because it can be changed into a prime (87477779) 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 as a sum of consecutive naturals, namely, 21869443 + ... + 21869446.

Almost surely, 2^87477778 is an apocalyptic number.

87477778 is a deficient number, since it is larger than the sum of its proper divisors (43738892).

87477778 is a wasteful number, since it uses less digits than its factorization.

87477778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43738891.

The product of its digits is 4302592, while the sum is 55.

The square root of 87477778 is about 9352.9555756456. The cubic root of 87477778 is about 443.9144148269.

The spelling of 87477778 in words is "eighty-seven million, four hundred seventy-seven thousand, seven hundred seventy-eight".