42573721 has 2 divisors, whose sum is σ = 42573722. Its totient is φ = 42573720.

The previous prime is 42573719. The next prime is 42573793. The reversal of 42573721 is 12737524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28772496 + 13801225 = 5364^2 + 3715^2 .

It is a cyclic number.

It is not a de Polignac number, because 42573721 - 2¹ = 42573719 is a prime.

Together with 42573719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42573701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21286860 + 21286861.

It is an arithmetic number, because the mean of its divisors is an integer number (21286861).

Almost surely, 2^42573721 is an apocalyptic number.

It is an amenable number.

42573721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42573721 is an equidigital number, since it uses as much as digits as its factorization.

42573721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11760, while the sum is 31.

The square root of 42573721 is about 6524.8540979856. The cubic root of 42573721 is about 349.1782654280.

The spelling of 42573721 in words is "forty-two million, five hundred seventy-three thousand, seven hundred twenty-one".