20516057 has 2 divisors, whose sum is σ = 20516058. Its totient is φ = 20516056.

The previous prime is 20516047. The next prime is 20516071. The reversal of 20516057 is 75061502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20394256 + 121801 = 4516^2 + 349^2 .

It is a cyclic number.

It is not a de Polignac number, because 20516057 - 2¹⁴ = 20499673 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20516047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258028 + 10258029.

It is an arithmetic number, because the mean of its divisors is an integer number (10258029).

Almost surely, 2^20516057 is an apocalyptic number.

It is an amenable number.

20516057 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516057 is an equidigital number, since it uses as much as digits as its factorization.

20516057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 20516057 is about 4529.4654209962. The cubic root of 20516057 is about 273.7566214004.

Adding to 20516057 its reverse (75061502), we get a palindrome (95577559).

The spelling of 20516057 in words is "twenty million, five hundred sixteen thousand, fifty-seven".