43049921 has 4 divisors (see below), whose sum is σ = 43364292. Its totient is φ = 42735552.

The previous prime is 43049893. The next prime is 43049947. The reversal of 43049921 is 12994034.

43049921 = 4639² + 4640².

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21529600 + 21520321 = 4640^2 + 4639^2 .

It is a cyclic number.

It is not a de Polignac number, because 43049921 - 2¹⁸ = 42787777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43049521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156980 + ... + 157253.

It is an arithmetic number, because the mean of its divisors is an integer number (10841073).

Almost surely, 2^43049921 is an apocalyptic number.

43049921 is the 4640-th centered square number.

It is an amenable number.

43049921 is a deficient number, since it is larger than the sum of its proper divisors (314371).

43049921 is a wasteful number, since it uses less digits than its factorization.

43049921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314370.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 43049921 is about 6561.2438607325. The cubic root of 43049921 is about 350.4753296800.

The spelling of 43049921 in words is "forty-three million, forty-nine thousand, nine hundred twenty-one".