78285887 has 4 divisors (see below), whose sum is σ = 79093056. Its totient is φ = 77478720.

The previous prime is 78285847. The next prime is 78285923. The reversal of 78285887 is 78858287.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78858287 = 1657 ⋅47591.

It is a cyclic number.

It is not a de Polignac number, because 78285887 - 2²⁰ = 77237311 is a prime.

It is a super-2 number, since 2×78285887² = 12257360206753538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78285817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 403439 + ... + 403632.

It is an arithmetic number, because the mean of its divisors is an integer number (19773264).

Almost surely, 2^78285887 is an apocalyptic number.

78285887 is a deficient number, since it is larger than the sum of its proper divisors (807169).

78285887 is an equidigital number, since it uses as much as digits as its factorization.

78285887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 807168.

The product of its digits is 2007040, while the sum is 53.

The square root of 78285887 is about 8847.9312271287. The cubic root of 78285887 is about 427.7872392178.

The spelling of 78285887 in words is "seventy-eight million, two hundred eighty-five thousand, eight hundred eighty-seven".