43871721 has 4 divisors (see below), whose sum is σ = 58495632. Its totient is φ = 29247812.

The previous prime is 43871701. The next prime is 43871761. The reversal of 43871721 is 12717834.

It is a happy number.

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 43871721 - 2⁵ = 43871689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (43871701) 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, 7311951 + ... + 7311956.

It is an arithmetic number, because the mean of its divisors is an integer number (14623908).

Almost surely, 2^43871721 is an apocalyptic number.

It is an amenable number.

43871721 is a deficient number, since it is larger than the sum of its proper divisors (14623911).

43871721 is a wasteful number, since it uses less digits than its factorization.

43871721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14623910.

The product of its digits is 9408, while the sum is 33.

The square root of 43871721 is about 6623.5731293615. The cubic root of 43871721 is about 352.6914165843.

The spelling of 43871721 in words is "forty-three million, eight hundred seventy-one thousand, seven hundred twenty-one".