13165525421 has 2 divisors, whose sum is σ = 13165525422. Its totient is φ = 13165525420.

The previous prime is 13165525409. The next prime is 13165525469. The reversal of 13165525421 is 12452556131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7849074025 + 5316451396 = 88595^2 + 72914^2 .

It is a cyclic number.

It is not a de Polignac number, because 13165525421 - 2¹⁸ = 13165263277 is a prime.

It is a super-2 number, since 2×13165525421² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13165525721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6582762710 + 6582762711.

It is an arithmetic number, because the mean of its divisors is an integer number (6582762711).

Almost surely, 2^13165525421 is an apocalyptic number.

It is an amenable number.

13165525421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13165525421 is an equidigital number, since it uses as much as digits as its factorization.

13165525421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36000, while the sum is 35.

The spelling of 13165525421 in words is "thirteen billion, one hundred sixty-five million, five hundred twenty-five thousand, four hundred twenty-one".