6551719997 has 4 divisors (see below), whose sum is σ = 6641469660. Its totient is φ = 6461970336.

The previous prime is 6551719987. The next prime is 6551720003. The reversal of 6551719997 is 7999171556.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4354548121 + 2197171876 = 65989^2 + 46874^2 .

It is a cyclic number.

It is not a de Polignac number, because 6551719997 - 2¹⁸ = 6551457853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6551719987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44874722 + ... + 44874867.

It is an arithmetic number, because the mean of its divisors is an integer number (1660367415).

Almost surely, 2^6551719997 is an apocalyptic number.

It is an amenable number.

6551719997 is a deficient number, since it is larger than the sum of its proper divisors (89749663).

6551719997 is an equidigital number, since it uses as much as digits as its factorization.

6551719997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89749662.

The product of its digits is 5358150, while the sum is 59.

The square root of 6551719997 is about 80942.6957606429. The cubic root of 6551719997 is about 1871.1923912631.

The spelling of 6551719997 in words is "six billion, five hundred fifty-one million, seven hundred nineteen thousand, nine hundred ninety-seven".