43193921 has 2 divisors, whose sum is σ = 43193922. Its totient is φ = 43193920.

The previous prime is 43193879. The next prime is 43193929. The reversal of 43193921 is 12939134.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27709696 + 15484225 = 5264^2 + 3935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43193921 is a prime.

It is a super-2 number, since 2×43193921² = 3731429622708482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (43193929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21596960 + 21596961.

It is an arithmetic number, because the mean of its divisors is an integer number (21596961).

Almost surely, 2^43193921 is an apocalyptic number.

It is an amenable number.

43193921 is a deficient number, since it is larger than the sum of its proper divisors (1).

43193921 is an equidigital number, since it uses as much as digits as its factorization.

43193921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 32.

The square root of 43193921 is about 6572.2082285941. The cubic root of 43193921 is about 350.8656693840.

The spelling of 43193921 in words is "forty-three million, one hundred ninety-three thousand, nine hundred twenty-one".