47811821 has 4 divisors (see below), whose sum is σ = 47839872. Its totient is φ = 47783772.

The previous prime is 47811793. The next prime is 47811823. The reversal of 47811821 is 12811874.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 47811821 - 2²² = 43617517 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 (47811823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11291 + ... + 14936.

It is an arithmetic number, because the mean of its divisors is an integer number (11959968).

Almost surely, 2^47811821 is an apocalyptic number.

It is an amenable number.

47811821 is a deficient number, since it is larger than the sum of its proper divisors (28051).

47811821 is a wasteful number, since it uses less digits than its factorization.

47811821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28050.

The product of its digits is 3584, while the sum is 32.

The square root of 47811821 is about 6914.6092442017. The cubic root of 47811821 is about 362.9485744502.

The spelling of 47811821 in words is "forty-seven million, eight hundred eleven thousand, eight hundred twenty-one".