42937721 has 2 divisors, whose sum is σ = 42937722. Its totient is φ = 42937720.

The previous prime is 42937703. The next prime is 42937751. The reversal of 42937721 is 12773924.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25806400 + 17131321 = 5080^2 + 4139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42937721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42937751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21468860 + 21468861.

It is an arithmetic number, because the mean of its divisors is an integer number (21468861).

Almost surely, 2^42937721 is an apocalyptic number.

It is an amenable number.

42937721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42937721 is an equidigital number, since it uses as much as digits as its factorization.

42937721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 35.

The square root of 42937721 is about 6552.6880743707. The cubic root of 42937721 is about 350.1705862324.

The spelling of 42937721 in words is "forty-two million, nine hundred thirty-seven thousand, seven hundred twenty-one".