100505105050561 has 2 divisors, whose sum is σ = 100505105050562. Its totient is φ = 100505105050560.

The previous prime is 100505105050523. The next prime is 100505105050631. The reversal of 100505105050561 is 165050501505001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51901131611536 + 48603973439025 = 7204244^2 + 6971655^2 .

It is a cyclic number.

It is not a de Polignac number, because 100505105050561 - 2¹⁷ = 100505104919489 is a prime.

It is a super-2 number, since 2×100505105050561² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (100505105057561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50252552525280 + 50252552525281.

It is an arithmetic number, because the mean of its divisors is an integer number (50252552525281).

Almost surely, 2^{100505105050561} is an apocalyptic number.

It is an amenable number.

100505105050561 is a deficient number, since it is larger than the sum of its proper divisors (1).

100505105050561 is an equidigital number, since it uses as much as digits as its factorization.

100505105050561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18750, while the sum is 34.

Adding to 100505105050561 its reverse (165050501505001), we get a palindrome (265555606555562).

The spelling of 100505105050561 in words is "one hundred trillion, five hundred five billion, one hundred five million, fifty thousand, five hundred sixty-one".