801642991609 has 2 divisors, whose sum is σ = 801642991610. Its totient is φ = 801642991608.

The previous prime is 801642991577. The next prime is 801642991673. The reversal of 801642991609 is 906199246108.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 796997206009 + 4645785600 = 892747^2 + 68160^2 .

It is a cyclic number.

It is not a de Polignac number, because 801642991609 - 2⁵ = 801642991577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 801642991609.

It is not a weakly prime, because it can be changed into another prime (801642991109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400821495804 + 400821495805.

It is an arithmetic number, because the mean of its divisors is an integer number (400821495805).

Almost surely, 2^801642991609 is an apocalyptic number.

It is an amenable number.

801642991609 is a deficient number, since it is larger than the sum of its proper divisors (1).

801642991609 is an equidigital number, since it uses as much as digits as its factorization.

801642991609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1679616, while the sum is 55.

The spelling of 801642991609 in words is "eight hundred one billion, six hundred forty-two million, nine hundred ninety-one thousand, six hundred nine".