21531533020069 has 2 divisors, whose sum is σ = 21531533020070. Its totient is φ = 21531533020068.

The previous prime is 21531533019961. The next prime is 21531533020103. The reversal of 21531533020069 is 96002033513512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21422179128100 + 109353891969 = 4628410^2 + 330687^2 .

It is a cyclic number.

It is not a de Polignac number, because 21531533020069 - 2⁴¹ = 19332509764517 is a prime.

It is a super-2 number, since 2×21531533020069² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21531533020769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10765766510034 + 10765766510035.

It is an arithmetic number, because the mean of its divisors is an integer number (10765766510035).

Almost surely, 2^{21531533020069} is an apocalyptic number.

It is an amenable number.

21531533020069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21531533020069 is an equidigital number, since it uses as much as digits as its factorization.

21531533020069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145800, while the sum is 40.

The spelling of 21531533020069 in words is "twenty-one trillion, five hundred thirty-one billion, five hundred thirty-three million, twenty thousand, sixty-nine".