47921 has 4 divisors (see below), whose sum is σ = 48372. Its totient is φ = 47472.

The previous prime is 47917. The next prime is 47933. The reversal of 47921 is 12974.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 26896 + 21025 = 164^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 47921 - 2² = 47917 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 47921.

It is not an unprimeable number, because it can be changed into a prime (47911) 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, 35 + ... + 311.

It is an arithmetic number, because the mean of its divisors is an integer number (12093).

2⁴⁷⁹²¹ is an apocalyptic number.

It is an amenable number.

47921 is a deficient number, since it is larger than the sum of its proper divisors (451).

47921 is a wasteful number, since it uses less digits than its factorization.

47921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450.

The product of its digits is 504, while the sum is 23.

The square root of 47921 is about 218.9086567498. The cubic root of 47921 is about 36.3224630576.

It can be divided in two parts, 4 and 7921, that multiplied together give a square (31684 = 178²).

The spelling of 47921 in words is "forty-seven thousand, nine hundred twenty-one".