78812215 has 4 divisors (see below), whose sum is σ = 94574664. Its totient is φ = 63049768.

The previous prime is 78812207. The next prime is 78812231. The reversal of 78812215 is 51221887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51221887 = 2801 ⋅18287.

It is a cyclic number.

It is not a de Polignac number, because 78812215 - 2³ = 78812207 is a prime.

It is a super-2 number, since 2×78812215² = 12422730466412450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 7881217 + ... + 7881226.

It is an arithmetic number, because the mean of its divisors is an integer number (23643666).

Almost surely, 2^78812215 is an apocalyptic number.

78812215 is a deficient number, since it is larger than the sum of its proper divisors (15762449).

78812215 is a wasteful number, since it uses less digits than its factorization.

78812215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15762448.

The product of its digits is 8960, while the sum is 34.

The square root of 78812215 is about 8877.6244007054. The cubic root of 78812215 is about 428.7437917542.

The spelling of 78812215 in words is "seventy-eight million, eight hundred twelve thousand, two hundred fifteen".