7897644817 has 4 divisors (see below), whose sum is σ = 7899358516. Its totient is φ = 7895931120.

The previous prime is 7897644739. The next prime is 7897644841. The reversal of 7897644817 is 7184467987.

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 4671859201 + 3225785616 = 68351^2 + 56796^2 .

It is a cyclic number.

It is not a de Polignac number, because 7897644817 - 2¹¹ = 7897642769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7897644017) 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, 849918 + ... + 859159.

It is an arithmetic number, because the mean of its divisors is an integer number (1974839629).

Almost surely, 2^7897644817 is an apocalyptic number.

It is an amenable number.

7897644817 is a deficient number, since it is larger than the sum of its proper divisors (1713699).

7897644817 is a wasteful number, since it uses less digits than its factorization.

7897644817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1713698.

The product of its digits is 18966528, while the sum is 61.

The square root of 7897644817 is about 88868.6942460617. The cubic root of 7897644817 is about 1991.4337635964.

The spelling of 7897644817 in words is "seven billion, eight hundred ninety-seven million, six hundred forty-four thousand, eight hundred seventeen".