100305121661 has 2 divisors, whose sum is σ = 100305121662. Its totient is φ = 100305121660.

The previous prime is 100305121649. The next prime is 100305121669. The reversal of 100305121661 is 166121503001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89859055225 + 10446066436 = 299765^2 + 102206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100305121661 is a prime.

It is a super-2 number, since 2×100305121661² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 100305121661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100305121669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50152560830 + 50152560831.

It is an arithmetic number, because the mean of its divisors is an integer number (50152560831).

Almost surely, 2^100305121661 is an apocalyptic number.

It is an amenable number.

100305121661 is a deficient number, since it is larger than the sum of its proper divisors (1).

100305121661 is an equidigital number, since it uses as much as digits as its factorization.

100305121661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

Adding to 100305121661 its reverse (166121503001), we get a palindrome (266426624662).

The spelling of 100305121661 in words is "one hundred billion, three hundred five million, one hundred twenty-one thousand, six hundred sixty-one".