78123513 has 16 divisors (see below), whose sum is σ = 112835520. Its totient is φ = 47793984.

The previous prime is 78123481. The next prime is 78123523. The reversal of 78123513 is 31532187.

It is not a de Polignac number, because 78123513 - 2⁵ = 78123481 is a prime.

It is a super-2 number, since 2×78123513² = 12206566566922338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78123523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 958 + ... + 12536.

It is an arithmetic number, because the mean of its divisors is an integer number (7052220).

Almost surely, 2^78123513 is an apocalyptic number.

It is an amenable number.

78123513 is a deficient number, since it is larger than the sum of its proper divisors (34712007).

78123513 is a wasteful number, since it uses less digits than its factorization.

78123513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11768.

The product of its digits is 5040, while the sum is 30.

The square root of 78123513 is about 8838.7506470089. The cubic root of 78123513 is about 427.4912744021.

It can be divided in two parts, 7812 and 3513, that added together give a triangular number (11325 = T₁₅₀).

The spelling of 78123513 in words is "seventy-eight million, one hundred twenty-three thousand, five hundred thirteen".