43875721 has 4 divisors (see below), whose sum is σ = 44002512. Its totient is φ = 43748932.

The previous prime is 43875707. The next prime is 43875739. The reversal of 43875721 is 12757834.

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 43875721 - 2⁷ = 43875593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43875791) 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, 62875 + ... + 63568.

It is an arithmetic number, because the mean of its divisors is an integer number (11000628).

Almost surely, 2^43875721 is an apocalyptic number.

It is an amenable number.

43875721 is a deficient number, since it is larger than the sum of its proper divisors (126791).

43875721 is a wasteful number, since it uses less digits than its factorization.

43875721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126790.

The product of its digits is 47040, while the sum is 37.

The square root of 43875721 is about 6623.8750743051. The cubic root of 43875721 is about 352.7021351274.

The spelling of 43875721 in words is "forty-three million, eight hundred seventy-five thousand, seven hundred twenty-one".