78438855 has 48 divisors (see below), whose sum is σ = 144023040. Its totient is φ = 36358080.

The previous prime is 78438851. The next prime is 78438869. The reversal of 78438855 is 55883487.

It is not a de Polignac number, because 78438855 - 2² = 78438851 is a prime.

It is a super-2 number, since 2×78438855² = 12305307947422050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78438851) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 40806 + ... + 42684.

It is an arithmetic number, because the mean of its divisors is an integer number (3000480).

Almost surely, 2^78438855 is an apocalyptic number.

78438855 is a deficient number, since it is larger than the sum of its proper divisors (65584185).

78438855 is a wasteful number, since it uses less digits than its factorization.

78438855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932 (or 1921 counting only the distinct ones).

The product of its digits is 1075200, while the sum is 48.

The square root of 78438855 is about 8856.5712891615. The cubic root of 78438855 is about 428.0656852488.

The spelling of 78438855 in words is "seventy-eight million, four hundred thirty-eight thousand, eight hundred fifty-five".