57016721 has 2 divisors, whose sum is σ = 57016722. Its totient is φ = 57016720.

The previous prime is 57016717. The next prime is 57016733. The reversal of 57016721 is 12761075.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55726225 + 1290496 = 7465^2 + 1136^2 .

It is a cyclic number.

It is not a de Polignac number, because 57016721 - 2² = 57016717 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (57016121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28508360 + 28508361.

It is an arithmetic number, because the mean of its divisors is an integer number (28508361).

Almost surely, 2^57016721 is an apocalyptic number.

It is an amenable number.

57016721 is a deficient number, since it is larger than the sum of its proper divisors (1).

57016721 is an equidigital number, since it uses as much as digits as its factorization.

57016721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 57016721 is about 7550.9417293474. The cubic root of 57016721 is about 384.8877414879.

Adding to 57016721 its reverse (12761075), we get a palindrome (69777796).

The spelling of 57016721 in words is "fifty-seven million, sixteen thousand, seven hundred twenty-one".