16531546397 has 2 divisors, whose sum is σ = 16531546398. Its totient is φ = 16531546396.

The previous prime is 16531546393. The next prime is 16531546481. The reversal of 16531546397 is 79364513561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14064536836 + 2467009561 = 118594^2 + 49669^2 .

It is a cyclic number.

It is not a de Polignac number, because 16531546397 - 2² = 16531546393 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16531546393) 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, 8265773198 + 8265773199.

It is an arithmetic number, because the mean of its divisors is an integer number (8265773199).

Almost surely, 2^16531546397 is an apocalyptic number.

It is an amenable number.

16531546397 is a deficient number, since it is larger than the sum of its proper divisors (1).

16531546397 is an equidigital number, since it uses as much as digits as its factorization.

16531546397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2041200, while the sum is 50.

The spelling of 16531546397 in words is "sixteen billion, five hundred thirty-one million, five hundred forty-six thousand, three hundred ninety-seven".