78137258585 has 12 divisors (see below), whose sum is σ = 95380900068. Its totient is φ = 61450304928.

The previous prime is 78137258581. The next prime is 78137258587. The reversal of 78137258585 is 58585273187.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15822620944 + 62314637641 = 125788^2 + 249629^2 .

It is not a de Polignac number, because 78137258585 - 2² = 78137258581 is a prime.

It is a super-2 number, since 2×78137258585² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (59) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (59).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78137258581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2227274 + ... + 2262083.

It is an arithmetic number, because the mean of its divisors is an integer number (7948408339).

Almost surely, 2^78137258585 is an apocalyptic number.

It is an amenable number.

78137258585 is a deficient number, since it is larger than the sum of its proper divisors (17243641483).

78137258585 is an equidigital number, since it uses as much as digits as its factorization.

78137258585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4489480 (or 4489421 counting only the distinct ones).

The product of its digits is 18816000, while the sum is 59.

The spelling of 78137258585 in words is "seventy-eight billion, one hundred thirty-seven million, two hundred fifty-eight thousand, five hundred eighty-five".