21165540152201 has 2 divisors, whose sum is σ = 21165540152202. Its totient is φ = 21165540152200.

The previous prime is 21165540152191. The next prime is 21165540152213. The reversal of 21165540152201 is 10225104556112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21094730410000 + 70809742201 = 4592900^2 + 266101^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21165540152201 is a prime.

It is not a weakly prime, because it can be changed into another prime (21165540151201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10582770076100 + 10582770076101.

It is an arithmetic number, because the mean of its divisors is an integer number (10582770076101).

Almost surely, 2^{21165540152201} is an apocalyptic number.

It is an amenable number.

21165540152201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21165540152201 is an equidigital number, since it uses as much as digits as its factorization.

21165540152201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24000, while the sum is 35.

The spelling of 21165540152201 in words is "twenty-one trillion, one hundred sixty-five billion, five hundred forty million, one hundred fifty-two thousand, two hundred one".