78144215 has 4 divisors (see below), whose sum is σ = 93773064. Its totient is φ = 62515368.

The previous prime is 78144197. The next prime is 78144217. The reversal of 78144215 is 51244187.

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: 51244187 = 131 ⋅391177.

It is a cyclic number.

It is not a de Polignac number, because 78144215 - 2⁶ = 78144151 is a prime.

It is a super-2 number, since 2×78144215² = 12213036675932450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78144217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7814417 + ... + 7814426.

It is an arithmetic number, because the mean of its divisors is an integer number (23443266).

Almost surely, 2^78144215 is an apocalyptic number.

78144215 is a deficient number, since it is larger than the sum of its proper divisors (15628849).

78144215 is a wasteful number, since it uses less digits than its factorization.

78144215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15628848.

The product of its digits is 8960, while the sum is 32.

The square root of 78144215 is about 8839.9216625488. The cubic root of 78144215 is about 427.5290314632.

The spelling of 78144215 in words is "seventy-eight million, one hundred forty-four thousand, two hundred fifteen".