16535531209 has 2 divisors, whose sum is σ = 16535531210. Its totient is φ = 16535531208.

The previous prime is 16535531171. The next prime is 16535531249. The reversal of 16535531209 is 90213553561.

It is an a-pointer prime, because the next prime (16535531249) can be obtained adding 16535531209 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16179076809 + 356454400 = 127197^2 + 18880^2 .

It is a cyclic number.

It is not a de Polignac number, because 16535531209 - 2³¹ = 14388047561 is a prime.

It is not a weakly prime, because it can be changed into another prime (16535531249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8267765604 + 8267765605.

It is an arithmetic number, because the mean of its divisors is an integer number (8267765605).

Almost surely, 2^16535531209 is an apocalyptic number.

It is an amenable number.

16535531209 is a deficient number, since it is larger than the sum of its proper divisors (1).

16535531209 is an equidigital number, since it uses as much as digits as its factorization.

16535531209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 121500, while the sum is 40.

The spelling of 16535531209 in words is "sixteen billion, five hundred thirty-five million, five hundred thirty-one thousand, two hundred nine".