47018721 has 4 divisors (see below), whose sum is σ = 62691632. Its totient is φ = 31345812.

The previous prime is 47018717. The next prime is 47018729. The reversal of 47018721 is 12781074.

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 47018721 - 2² = 47018717 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (47018729) 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, 7836451 + ... + 7836456.

It is an arithmetic number, because the mean of its divisors is an integer number (15672908).

Almost surely, 2^47018721 is an apocalyptic number.

It is an amenable number.

47018721 is a deficient number, since it is larger than the sum of its proper divisors (15672911).

47018721 is a wasteful number, since it uses less digits than its factorization.

47018721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15672910.

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 47018721 is about 6857.0198337179. The cubic root of 47018721 is about 360.9305171378.

Adding to 47018721 its reverse (12781074), we get a palindrome (59799795).

It can be divided in two parts, 470 and 18721, that added together give a palindrome (19191).

The spelling of 47018721 in words is "forty-seven million, eighteen thousand, seven hundred twenty-one".