165541621406929 has 2 divisors, whose sum is σ = 165541621406930. Its totient is φ = 165541621406928.

The previous prime is 165541621406911. The next prime is 165541621406939. The reversal of 165541621406929 is 929604126145561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84479995690000 + 81061625716929 = 9191300^2 + 9003423^2 .

It is an emirp because it is prime and its reverse (929604126145561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165541621406929 - 2²⁵ = 165541587852497 is a prime.

It is a super-2 number, since 2×165541621406929² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165541621406939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82770810703464 + 82770810703465.

It is an arithmetic number, because the mean of its divisors is an integer number (82770810703465).

Almost surely, 2^{165541621406929} is an apocalyptic number.

It is an amenable number.

165541621406929 is a deficient number, since it is larger than the sum of its proper divisors (1).

165541621406929 is an equidigital number, since it uses as much as digits as its factorization.

165541621406929 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27993600, while the sum is 61.

The spelling of 165541621406929 in words is "one hundred sixty-five trillion, five hundred forty-one billion, six hundred twenty-one million, four hundred six thousand, nine hundred twenty-nine".