78215903 has 4 divisors (see below), whose sum is σ = 78786960. Its totient is φ = 77644848.

The previous prime is 78215897. The next prime is 78215909. The reversal of 78215903 is 30951287.

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

It is an interprime number because it is at equal distance from previous prime (78215897) and next prime (78215909).

It is a cyclic number.

It is not a de Polignac number, because 78215903 - 2¹⁰ = 78214879 is a prime.

It is a super-2 number, since 2×78215903² = 12235454964210818, 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 (78215909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 285323 + ... + 285596.

It is an arithmetic number, because the mean of its divisors is an integer number (19696740).

Almost surely, 2^78215903 is an apocalyptic number.

78215903 is a deficient number, since it is larger than the sum of its proper divisors (571057).

78215903 is a wasteful number, since it uses less digits than its factorization.

78215903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571056.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 78215903 is about 8843.9755200928. The cubic root of 78215903 is about 427.6597271426.

The spelling of 78215903 in words is "seventy-eight million, two hundred fifteen thousand, nine hundred three".