78447157 has 8 divisors (see below), whose sum is σ = 79369632. Its totient is φ = 77528400.

The previous prime is 78447137. The next prime is 78447221. The reversal of 78447157 is 75174487.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78447157 - 2¹⁹ = 77922869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78447107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73407 + ... + 74467.

It is an arithmetic number, because the mean of its divisors is an integer number (9921204).

Almost surely, 2^78447157 is an apocalyptic number.

It is an amenable number.

78447157 is a deficient number, since it is larger than the sum of its proper divisors (922475).

78447157 is a wasteful number, since it uses less digits than its factorization.

78447157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1859.

The product of its digits is 219520, while the sum is 43.

The square root of 78447157 is about 8857.0399682964. The cubic root of 78447157 is about 428.0807869308.

The spelling of 78447157 in words is "seventy-eight million, four hundred forty-seven thousand, one hundred fifty-seven".