43307921 has 2 divisors, whose sum is σ = 43307922. Its totient is φ = 43307920.

The previous prime is 43307903. The next prime is 43307969. The reversal of 43307921 is 12970334.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37994896 + 5313025 = 6164^2 + 2305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43307921 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (43307981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21653960 + 21653961.

It is an arithmetic number, because the mean of its divisors is an integer number (21653961).

Almost surely, 2^43307921 is an apocalyptic number.

It is an amenable number.

43307921 is a deficient number, since it is larger than the sum of its proper divisors (1).

43307921 is an equidigital number, since it uses as much as digits as its factorization.

43307921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 43307921 is about 6580.8753976960. The cubic root of 43307921 is about 351.1740734982.

The spelling of 43307921 in words is "forty-three million, three hundred seven thousand, nine hundred twenty-one".