47815391 has 4 divisors (see below), whose sum is σ = 51493512. Its totient is φ = 44137272.

The previous prime is 47815379. The next prime is 47815451. The reversal of 47815391 is 19351874.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-47815391 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 (47815331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1839041 + ... + 1839066.

It is an arithmetic number, because the mean of its divisors is an integer number (12873378).

Almost surely, 2^47815391 is an apocalyptic number.

47815391 is a deficient number, since it is larger than the sum of its proper divisors (3678121).

47815391 is a wasteful number, since it uses less digits than its factorization.

47815391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3678120.

The product of its digits is 30240, while the sum is 38.

The square root of 47815391 is about 6914.8673884609. The cubic root of 47815391 is about 362.9576077404.

The spelling of 47815391 in words is "forty-seven million, eight hundred fifteen thousand, three hundred ninety-one".