78394515 has 8 divisors (see below), whose sum is σ = 125431248. Its totient is φ = 41810400.

The previous prime is 78394507. The next prime is 78394517. The reversal of 78394515 is 51549387.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78394515 - 2³ = 78394507 is a prime.

It is a super-2 number, since 2×78394515² = 12291399964170450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78394517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2613136 + ... + 2613165.

It is an arithmetic number, because the mean of its divisors is an integer number (15678906).

Almost surely, 2^78394515 is an apocalyptic number.

78394515 is a deficient number, since it is larger than the sum of its proper divisors (47036733).

78394515 is a wasteful number, since it uses less digits than its factorization.

78394515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5226309.

The product of its digits is 151200, while the sum is 42.

The square root of 78394515 is about 8854.0677092509. The cubic root of 78394515 is about 427.9850109026.

The spelling of 78394515 in words is "seventy-eight million, three hundred ninety-four thousand, five hundred fifteen".