47851821 has 12 divisors (see below), whose sum is σ = 73185372. Its totient is φ = 30024576.

The previous prime is 47851813. The next prime is 47851831. The reversal of 47851821 is 12815874.

47851821 is a `hidden beast` number, since 478 + 5 + 182 + 1 = 666.

47851821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 38303721 + 9548100 = 6189^2 + 3090^2 .

It is not a de Polignac number, because 47851821 - 2³ = 47851813 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47851831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 156226 + ... + 156531.

It is an arithmetic number, because the mean of its divisors is an integer number (6098781).

Almost surely, 2^47851821 is an apocalyptic number.

It is an amenable number.

47851821 is a deficient number, since it is larger than the sum of its proper divisors (25333551).

47851821 is a wasteful number, since it uses less digits than its factorization.

47851821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312780 (or 312777 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 47851821 is about 6917.5010661365. The cubic root of 47851821 is about 363.0497620918.

The spelling of 47851821 in words is "forty-seven million, eight hundred fifty-one thousand, eight hundred twenty-one".