78170013 has 6 divisors (see below), whose sum is σ = 112912254. Its totient is φ = 52113336.

The previous prime is 78169999. The next prime is 78170021. The reversal of 78170013 is 31007187.

It can be written as a sum of positive squares in only one way, i.e., 40678884 + 37491129 = 6378^2 + 6123^2 .

It is not a de Polignac number, because 78170013 - 2¹⁰ = 78168989 is a prime.

It is a super-2 number, since 2×78170013² = 12221101864840338, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78170023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4342770 + ... + 4342787.

It is an arithmetic number, because the mean of its divisors is an integer number (18818709).

Almost surely, 2^78170013 is an apocalyptic number.

It is an amenable number.

78170013 is a deficient number, since it is larger than the sum of its proper divisors (34742241).

78170013 is a wasteful number, since it uses less digits than its factorization.

78170013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8685563 (or 8685560 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The square root of 78170013 is about 8841.3807179648. The cubic root of 78170013 is about 427.5760734631.

The spelling of 78170013 in words is "seventy-eight million, one hundred seventy thousand, thirteen".