21161005500149 has 2 divisors, whose sum is σ = 21161005500150. Its totient is φ = 21161005500148.

The previous prime is 21161005500121. The next prime is 21161005500233. The reversal of 21161005500149 is 94100550016112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16731167640625 + 4429837859524 = 4090375^2 + 2104718^2 .

It is a cyclic number.

It is not a de Polignac number, because 21161005500149 - 2¹² = 21161005496053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21161005530149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10580502750074 + 10580502750075.

It is an arithmetic number, because the mean of its divisors is an integer number (10580502750075).

Almost surely, 2^{21161005500149} is an apocalyptic number.

It is an amenable number.

21161005500149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21161005500149 is an equidigital number, since it uses as much as digits as its factorization.

21161005500149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 35.

The spelling of 21161005500149 in words is "twenty-one trillion, one hundred sixty-one billion, five million, five hundred thousand, one hundred forty-nine".