78285617 has 4 divisors (see below), whose sum is σ = 78413940. Its totient is φ = 78157296.

The previous prime is 78285607. The next prime is 78285677. The reversal of 78285617 is 71658287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71658287 = 3907 ⋅18341.

It can be written as a sum of positive squares in 2 ways, for example, as 9991921 + 68293696 = 3161^2 + 8264^2 .

It is a cyclic number.

It is not a de Polignac number, because 78285617 - 2⁴ = 78285601 is a prime.

It is a super-2 number, since 2×78285617² = 12257275658141378, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78285607) 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, 63242 + ... + 64467.

It is an arithmetic number, because the mean of its divisors is an integer number (19603485).

Almost surely, 2^78285617 is an apocalyptic number.

It is an amenable number.

78285617 is a deficient number, since it is larger than the sum of its proper divisors (128323).

78285617 is a wasteful number, since it uses less digits than its factorization.

78285617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128322.

The product of its digits is 188160, while the sum is 44.

The square root of 78285617 is about 8847.9159693116. The cubic root of 78285617 is about 427.7867474191.

The spelling of 78285617 in words is "seventy-eight million, two hundred eighty-five thousand, six hundred seventeen".