78315415 has 4 divisors (see below), whose sum is σ = 93978504. Its totient is φ = 62652328.

The previous prime is 78315409. The next prime is 78315449. The reversal of 78315415 is 51451387.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51451387 = 13 ⋅3957799.

It is a cyclic number.

It is not a de Polignac number, because 78315415 - 2³ = 78315407 is a prime.

It is a super-2 number, since 2×78315415² = 12266608453244450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7831537 + ... + 7831546.

It is an arithmetic number, because the mean of its divisors is an integer number (23494626).

Almost surely, 2^78315415 is an apocalyptic number.

78315415 is a deficient number, since it is larger than the sum of its proper divisors (15663089).

78315415 is a wasteful number, since it uses less digits than its factorization.

78315415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15663088.

The product of its digits is 16800, while the sum is 34.

The square root of 78315415 is about 8849.5997084614. The cubic root of 78315415 is about 427.8410169559.

The spelling of 78315415 in words is "seventy-eight million, three hundred fifteen thousand, four hundred fifteen".