78785137 has 4 divisors (see below), whose sum is σ = 79220596. Its totient is φ = 78349680.

The previous prime is 78785131. The next prime is 78785197. The reversal of 78785137 is 73158787.

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: 73158787 = 13 ⋅5627599.

It can be written as a sum of positive squares in 2 ways, for example, as 6806881 + 71978256 = 2609^2 + 8484^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78785137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78785131) 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, 217458 + ... + 217819.

It is an arithmetic number, because the mean of its divisors is an integer number (19805149).

Almost surely, 2^78785137 is an apocalyptic number.

It is an amenable number.

78785137 is a deficient number, since it is larger than the sum of its proper divisors (435459).

78785137 is a wasteful number, since it uses less digits than its factorization.

78785137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435458.

The product of its digits is 329280, while the sum is 46.

The square root of 78785137 is about 8876.0991995358. The cubic root of 78785137 is about 428.6946840779.

The spelling of 78785137 in words is "seventy-eight million, seven hundred eighty-five thousand, one hundred thirty-seven".