78215855 has 8 divisors (see below), whose sum is σ = 93906864. Its totient is φ = 62540800.

The previous prime is 78215843. The next prime is 78215873. The reversal of 78215855 is 55851287.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78215855 - 2⁶ = 78215791 is a prime.

It is a super-3 number, since 3×78215855³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 7 ways as a sum of consecutive naturals, for example, 15215 + ... + 19695.

It is an arithmetic number, because the mean of its divisors is an integer number (11738358).

Almost surely, 2^78215855 is an apocalyptic number.

78215855 is a deficient number, since it is larger than the sum of its proper divisors (15691009).

78215855 is a wasteful number, since it uses less digits than its factorization.

78215855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7977.

The product of its digits is 112000, while the sum is 41.

The square root of 78215855 is about 8843.9728063806. The cubic root of 78215855 is about 427.6596396597.

The spelling of 78215855 in words is "seventy-eight million, two hundred fifteen thousand, eight hundred fifty-five".