87778 has 4 divisors (see below), whose sum is σ = 131670. Its totient is φ = 43888.

The previous prime is 87767. The next prime is 87793.

87778 is nontrivially palindromic in base 10.

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

It can be written as a sum of positive squares in only one way, i.e., 54289 + 33489 = 233^2 + 183^2 .

It is a congruent number.

It is an unprimeable number.

87778 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21943 + ... + 21946.

2⁸⁷⁷⁷⁸ is an apocalyptic number.

87778 is a deficient number, since it is larger than the sum of its proper divisors (43892).

87778 is a wasteful number, since it uses less digits than its factorization.

87778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43891.

The product of its digits is 21952, while the sum is 37.

The square root of 87778 is about 296.2735222729. The cubic root of 87778 is about 44.4421670129.

The spelling of 87778 in words is "eighty-seven thousand, seven hundred seventy-eight".