47072721 has 4 divisors (see below), whose sum is σ = 62763632. Its totient is φ = 31381812.

The previous prime is 47072719. The next prime is 47072741. The reversal of 47072721 is 12727074.

47072721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 47072721 - 2¹ = 47072719 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (47072741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7845451 + ... + 7845456.

It is an arithmetic number, because the mean of its divisors is an integer number (15690908).

Almost surely, 2^47072721 is an apocalyptic number.

It is an amenable number.

47072721 is a deficient number, since it is larger than the sum of its proper divisors (15690911).

47072721 is a wasteful number, since it uses less digits than its factorization.

47072721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15690910.

The product of its (nonzero) digits is 5488, while the sum is 30.

The square root of 47072721 is about 6860.9562744562. The cubic root of 47072721 is about 361.0686379465.

Adding to 47072721 its reverse (12727074), we get a palindrome (59799795).

The spelling of 47072721 in words is "forty-seven million, seventy-two thousand, seven hundred twenty-one".