47916721 has 4 divisors (see below), whose sum is σ = 47944512. Its totient is φ = 47888932.

The previous prime is 47916697. The next prime is 47916767. The reversal of 47916721 is 12761974.

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 47916721 - 2⁷ = 47916593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (47910721) 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, 11125 + ... + 14818.

It is an arithmetic number, because the mean of its divisors is an integer number (11986128).

Almost surely, 2^47916721 is an apocalyptic number.

It is an amenable number.

47916721 is a deficient number, since it is larger than the sum of its proper divisors (27791).

47916721 is a wasteful number, since it uses less digits than its factorization.

47916721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27790.

The product of its digits is 21168, while the sum is 37.

The square root of 47916721 is about 6922.1904770094. The cubic root of 47916721 is about 363.2138191397.

The spelling of 47916721 in words is "forty-seven million, nine hundred sixteen thousand, seven hundred twenty-one".