6687391553 has 2 divisors, whose sum is σ = 6687391554. Its totient is φ = 6687391552.

The previous prime is 6687391531. The next prime is 6687391567. The reversal of 6687391553 is 3551937866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6047706289 + 639685264 = 77767^2 + 25292^2 .

It is a cyclic number.

It is not a de Polignac number, because 6687391553 - 2⁶ = 6687391489 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6687391495 and 6687391504.

It is not a weakly prime, because it can be changed into another prime (6687391583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343695776 + 3343695777.

It is an arithmetic number, because the mean of its divisors is an integer number (3343695777).

Almost surely, 2^6687391553 is an apocalyptic number.

It is an amenable number.

6687391553 is a deficient number, since it is larger than the sum of its proper divisors (1).

6687391553 is an equidigital number, since it uses as much as digits as its factorization.

6687391553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4082400, while the sum is 53.

The square root of 6687391553 is about 81776.4731019870. The cubic root of 6687391553 is about 1884.0203267453.

The spelling of 6687391553 in words is "six billion, six hundred eighty-seven million, three hundred ninety-one thousand, five hundred fifty-three".