78441505 has 4 divisors (see below), whose sum is σ = 94129812. Its totient is φ = 62753200.

The previous prime is 78441469. The next prime is 78441509. The reversal of 78441505 is 50514487.

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

It can be written as a sum of positive squares in 2 ways, for example, as 29203216 + 49238289 = 5404^2 + 7017^2 .

It is not a de Polignac number, because 78441505 - 2⁹ = 78440993 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (78441509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7844146 + ... + 7844155.

It is an arithmetic number, because the mean of its divisors is an integer number (23532453).

Almost surely, 2^78441505 is an apocalyptic number.

It is an amenable number.

78441505 is a deficient number, since it is larger than the sum of its proper divisors (15688307).

78441505 is a wasteful number, since it uses less digits than its factorization.

78441505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15688306.

The product of its (nonzero) digits is 22400, while the sum is 34.

The square root of 78441505 is about 8856.7208943265. The cubic root of 78441505 is about 428.0705058244.

The spelling of 78441505 in words is "seventy-eight million, four hundred forty-one thousand, five hundred five".