10200121661 has 2 divisors, whose sum is σ = 10200121662. Its totient is φ = 10200121660.

The previous prime is 10200121651. The next prime is 10200121663. The reversal of 10200121661 is 16612100201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8870060761 + 1330060900 = 94181^2 + 36470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10200121661 is a prime.

Together with 10200121663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10200121663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5100060830 + 5100060831.

It is an arithmetic number, because the mean of its divisors is an integer number (5100060831).

Almost surely, 2^10200121661 is an apocalyptic number.

It is an amenable number.

10200121661 is a deficient number, since it is larger than the sum of its proper divisors (1).

10200121661 is an equidigital number, since it uses as much as digits as its factorization.

10200121661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 10200121661 its reverse (16612100201), we get a palindrome (26812221862).

The spelling of 10200121661 in words is "ten billion, two hundred million, one hundred twenty-one thousand, six hundred sixty-one".