47057821 has 4 divisors (see below), whose sum is σ = 48329692. Its totient is φ = 45785952.

The previous prime is 47057809. The next prime is 47057827. The reversal of 47057821 is 12875074.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12875074 = 2 ⋅6437537.

It can be written as a sum of positive squares in 2 ways, for example, as 23912100 + 23145721 = 4890^2 + 4811^2 .

It is a cyclic number.

It is not a de Polignac number, because 47057821 - 2⁵ = 47057789 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 (47057827) 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, 635880 + ... + 635953.

It is an arithmetic number, because the mean of its divisors is an integer number (12082423).

Almost surely, 2^47057821 is an apocalyptic number.

It is an amenable number.

47057821 is a deficient number, since it is larger than the sum of its proper divisors (1271871).

47057821 is a wasteful number, since it uses less digits than its factorization.

47057821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1271870.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 47057821 is about 6859.8703340515. The cubic root of 47057821 is about 361.0305373911.

The spelling of 47057821 in words is "forty-seven million, fifty-seven thousand, eight hundred twenty-one".