78109378 has 4 divisors (see below), whose sum is σ = 117164070. Its totient is φ = 39054688.

The previous prime is 78109363. The next prime is 78109379. The reversal of 78109378 is 87390187.

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

It can be written as a sum of positive squares in only one way, i.e., 60326289 + 17783089 = 7767^2 + 4217^2 .

It is a super-2 number, since 2×78109378² = 12202149863093768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78109379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19527343 + ... + 19527346.

Almost surely, 2^78109378 is an apocalyptic number.

78109378 is a deficient number, since it is larger than the sum of its proper divisors (39054692).

78109378 is a wasteful number, since it uses less digits than its factorization.

78109378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39054691.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 78109378 is about 8837.9510068794. The cubic root of 78109378 is about 427.4654906425.

It can be divided in two parts, 78109 and 378, that added together give a palindrome (78487).

The spelling of 78109378 in words is "seventy-eight million, one hundred nine thousand, three hundred seventy-eight".