78171513 has 24 divisors (see below), whose sum is σ = 123070752. Its totient is φ = 43997184.

The previous prime is 78171409. The next prime is 78171517. The reversal of 78171513 is 31517187.

It is not a de Polignac number, because 78171513 - 2¹⁷ = 78040441 is a prime.

It is a super-2 number, since 2×78171513² = 12221570889418338, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78171517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5881 + ... + 13817.

It is an arithmetic number, because the mean of its divisors is an integer number (5127948).

Almost surely, 2^78171513 is an apocalyptic number.

It is an amenable number.

78171513 is a deficient number, since it is larger than the sum of its proper divisors (44899239).

78171513 is a wasteful number, since it uses less digits than its factorization.

78171513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8021 (or 8014 counting only the distinct ones).

The product of its digits is 5880, while the sum is 33.

The square root of 78171513 is about 8841.4655459375. The cubic root of 78171513 is about 427.5788083567.

The spelling of 78171513 in words is "seventy-eight million, one hundred seventy-one thousand, five hundred thirteen".