6690717989 has 4 divisors (see below), whose sum is σ = 6697025100. Its totient is φ = 6684410880.

The previous prime is 6690717959. The next prime is 6690717991. The reversal of 6690717989 is 9897170966.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9897170966 = 2 ⋅4948585483.

It can be written as a sum of positive squares in 2 ways, for example, as 2541168100 + 4149549889 = 50410^2 + 64417^2 .

It is a cyclic number.

It is not a de Polignac number, because 6690717989 - 2¹⁶ = 6690652453 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 (6690717959) 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, 3151964 + ... + 3154085.

It is an arithmetic number, because the mean of its divisors is an integer number (1674256275).

Almost surely, 2^6690717989 is an apocalyptic number.

It is an amenable number.

6690717989 is a deficient number, since it is larger than the sum of its proper divisors (6307111).

6690717989 is a wasteful number, since it uses less digits than its factorization.

6690717989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6307110.

The product of its (nonzero) digits is 10287648, while the sum is 62.

The square root of 6690717989 is about 81796.8091614826. The cubic root of 6690717989 is about 1884.3326575027.

The spelling of 6690717989 in words is "six billion, six hundred ninety million, seven hundred seventeen thousand, nine hundred eighty-nine".