16620161506549 has 2 divisors, whose sum is σ = 16620161506550. Its totient is φ = 16620161506548.

The previous prime is 16620161506517. The next prime is 16620161506643. The reversal of 16620161506549 is 94560516102661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12272340176100 + 4347821330449 = 3503190^2 + 2085143^2 .

It is a cyclic number.

It is not a de Polignac number, because 16620161506549 - 2⁵ = 16620161506517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16620161506496 and 16620161506505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16620161501549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8310080753274 + 8310080753275.

It is an arithmetic number, because the mean of its divisors is an integer number (8310080753275).

Almost surely, 2^{16620161506549} is an apocalyptic number.

It is an amenable number.

16620161506549 is a deficient number, since it is larger than the sum of its proper divisors (1).

16620161506549 is an equidigital number, since it uses as much as digits as its factorization.

16620161506549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2332800, while the sum is 52.

The spelling of 16620161506549 in words is "sixteen trillion, six hundred twenty billion, one hundred sixty-one million, five hundred six thousand, five hundred forty-nine".