78140915 has 4 divisors (see below), whose sum is σ = 93769104. Its totient is φ = 62512728.

The previous prime is 78140903. The next prime is 78140917. The reversal of 78140915 is 51904187.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78140915 - 2⁴ = 78140899 is a prime.

It is a super-2 number, since 2×78140915² = 12212005194074450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78140917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7814087 + ... + 7814096.

It is an arithmetic number, because the mean of its divisors is an integer number (23442276).

Almost surely, 2^78140915 is an apocalyptic number.

78140915 is a deficient number, since it is larger than the sum of its proper divisors (15628189).

78140915 is a wasteful number, since it uses less digits than its factorization.

78140915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15628188.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 78140915 is about 8839.7350073404. The cubic root of 78140915 is about 427.5230132499.

The spelling of 78140915 in words is "seventy-eight million, one hundred forty thousand, nine hundred fifteen".