100561240992809 has 2 divisors, whose sum is σ = 100561240992810. Its totient is φ = 100561240992808.

The previous prime is 100561240992799. The next prime is 100561240992833. The reversal of 100561240992809 is 908299042165001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86352321834025 + 14208919158784 = 9292595^2 + 3769472^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100561240992809 is a prime.

It is a super-2 number, since 2×100561240992809² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (100561240992409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50280620496404 + 50280620496405.

It is an arithmetic number, because the mean of its divisors is an integer number (50280620496405).

Almost surely, 2^{100561240992809} is an apocalyptic number.

It is an amenable number.

100561240992809 is a deficient number, since it is larger than the sum of its proper divisors (1).

100561240992809 is an equidigital number, since it uses as much as digits as its factorization.

100561240992809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2799360, while the sum is 56.

The spelling of 100561240992809 in words is "one hundred trillion, five hundred sixty-one billion, two hundred forty million, nine hundred ninety-two thousand, eight hundred nine".