78634641 has 4 divisors (see below), whose sum is σ = 104846192. Its totient is φ = 52423092.

The previous prime is 78634627. The next prime is 78634643. The reversal of 78634641 is 14643687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 78634641 - 2⁷ = 78634513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78634641.

It is not an unprimeable number, because it can be changed into a prime (78634643) 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, 13105771 + ... + 13105776.

It is an arithmetic number, because the mean of its divisors is an integer number (26211548).

Almost surely, 2^78634641 is an apocalyptic number.

It is an amenable number.

78634641 is a deficient number, since it is larger than the sum of its proper divisors (26211551).

78634641 is a wasteful number, since it uses less digits than its factorization.

78634641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26211550.

The product of its digits is 96768, while the sum is 39.

The square root of 78634641 is about 8867.6175492632. The cubic root of 78634641 is about 428.4215447461.

The spelling of 78634641 in words is "seventy-eight million, six hundred thirty-four thousand, six hundred forty-one".