47857821 has 8 divisors (see below), whose sum is σ = 69611424. Its totient is φ = 29004720.

The previous prime is 47857819. The next prime is 47857829. The reversal of 47857821 is 12875874.

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

It is not a de Polignac number, because 47857821 - 2¹ = 47857819 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47857829) 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, 725086 + ... + 725151.

It is an arithmetic number, because the mean of its divisors is an integer number (8701428).

Almost surely, 2^47857821 is an apocalyptic number.

It is an amenable number.

47857821 is a deficient number, since it is larger than the sum of its proper divisors (21753603).

47857821 is a wasteful number, since it uses less digits than its factorization.

47857821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450251.

The product of its digits is 125440, while the sum is 42.

The square root of 47857821 is about 6917.9347351648. The cubic root of 47857821 is about 363.0649353739.

The spelling of 47857821 in words is "forty-seven million, eight hundred fifty-seven thousand, eight hundred twenty-one".