47147821 has 4 divisors (see below), whose sum is σ = 53883232. Its totient is φ = 40412412.

The previous prime is 47147809. The next prime is 47147831. The reversal of 47147821 is 12874174.

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 47147821 - 2²³ = 38759213 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 (47147801) 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, 3367695 + ... + 3367708.

It is an arithmetic number, because the mean of its divisors is an integer number (13470808).

Almost surely, 2^47147821 is an apocalyptic number.

It is an amenable number.

47147821 is a deficient number, since it is larger than the sum of its proper divisors (6735411).

47147821 is an equidigital number, since it uses as much as digits as its factorization.

47147821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6735410.

The product of its digits is 12544, while the sum is 34.

The square root of 47147821 is about 6866.4270912899. The cubic root of 47147821 is about 361.2605526864.

The spelling of 47147821 in words is "forty-seven million, one hundred forty-seven thousand, eight hundred twenty-one".