85705778 has 4 divisors (see below), whose sum is σ = 128558670. Its totient is φ = 42852888.

The previous prime is 85705771. The next prime is 85705783. The reversal of 85705778 is 87750758.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87750758 = 2 ⋅43875379.

It can be written as a sum of positive squares in only one way, i.e., 79085449 + 6620329 = 8893^2 + 2573^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (85705771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21426443 + ... + 21426446.

Almost surely, 2^85705778 is an apocalyptic number.

85705778 is a deficient number, since it is larger than the sum of its proper divisors (42852892).

85705778 is a wasteful number, since it uses less digits than its factorization.

85705778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42852891.

The product of its (nonzero) digits is 548800, while the sum is 47.

The square root of 85705778 is about 9257.7415172384. The cubic root of 85705778 is about 440.8965500357.

The spelling of 85705778 in words is "eighty-five million, seven hundred five thousand, seven hundred seventy-eight".