47904821 has 4 divisors (see below), whose sum is σ = 48249600. Its totient is φ = 47560044.

The previous prime is 47904817. The next prime is 47904859. The reversal of 47904821 is 12840974.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12840974 = 2 ⋅6420487.

It is a cyclic number.

It is not a de Polignac number, because 47904821 - 2² = 47904817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43904821) 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, 172181 + ... + 172458.

It is an arithmetic number, because the mean of its divisors is an integer number (12062400).

Almost surely, 2^47904821 is an apocalyptic number.

It is an amenable number.

47904821 is a deficient number, since it is larger than the sum of its proper divisors (344779).

47904821 is a wasteful number, since it uses less digits than its factorization.

47904821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344778.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 47904821 is about 6921.3308691320. The cubic root of 47904821 is about 363.1837488969.

The spelling of 47904821 in words is "forty-seven million, nine hundred four thousand, eight hundred twenty-one".