47991917 has 8 divisors (see below), whose sum is σ = 48537600. Its totient is φ = 47449584.

The previous prime is 47991907. The next prime is 47991971. The reversal of 47991917 is 71919974.

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 47991917 - 2¹⁴ = 47975533 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 (47991907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36884 + ... + 38162.

It is an arithmetic number, because the mean of its divisors is an integer number (6067200).

Almost surely, 2^47991917 is an apocalyptic number.

It is an amenable number.

47991917 is a deficient number, since it is larger than the sum of its proper divisors (545683).

47991917 is a wasteful number, since it uses less digits than its factorization.

47991917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1675.

The product of its digits is 142884, while the sum is 47.

The square root of 47991917 is about 6927.6198654372. The cubic root of 47991917 is about 363.4037177188.

The spelling of 47991917 in words is "forty-seven million, nine hundred ninety-one thousand, nine hundred seventeen".