78647906 has 4 divisors (see below), whose sum is σ = 117971862. Its totient is φ = 39323952.

The previous prime is 78647893. The next prime is 78647909. The reversal of 78647906 is 60974687.

It is a happy number.

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., 59367025 + 19280881 = 7705^2 + 4391^2 .

It is not an unprimeable number, because it can be changed into a prime (78647909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19661975 + ... + 19661978.

Almost surely, 2^78647906 is an apocalyptic number.

78647906 is a deficient number, since it is larger than the sum of its proper divisors (39323956).

78647906 is a wasteful number, since it uses less digits than its factorization.

78647906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39323955.

The product of its (nonzero) digits is 508032, while the sum is 47.

The square root of 78647906 is about 8868.3654638270. The cubic root of 78647906 is about 428.4456337574.

The spelling of 78647906 in words is "seventy-eight million, six hundred forty-seven thousand, nine hundred six".