20102105657 has 2 divisors, whose sum is σ = 20102105658. Its totient is φ = 20102105656.

The previous prime is 20102105633. The next prime is 20102105663. The reversal of 20102105657 is 75650120102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14357072041 + 5745033616 = 119821^2 + 75796^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20102105657 is a prime.

It is not a weakly prime, because it can be changed into another prime (20102155657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10051052828 + 10051052829.

It is an arithmetic number, because the mean of its divisors is an integer number (10051052829).

Almost surely, 2^20102105657 is an apocalyptic number.

It is an amenable number.

20102105657 is a deficient number, since it is larger than the sum of its proper divisors (1).

20102105657 is an equidigital number, since it uses as much as digits as its factorization.

20102105657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4200, while the sum is 29.

Adding to 20102105657 its reverse (75650120102), we get a palindrome (95752225759).

The spelling of 20102105657 in words is "twenty billion, one hundred two million, one hundred five thousand, six hundred fifty-seven".