19995904945 has 4 divisors (see below), whose sum is σ = 23995085940. Its totient is φ = 15996723952.

The previous prime is 19995904939. The next prime is 19995904963. The reversal of 19995904945 is 54940959991.

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 2042316864 + 17953588081 = 45192^2 + 133991^2 .

It is a cyclic number.

It is not a de Polignac number, because 19995904945 - 2¹⁵ = 19995872177 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1999590490 + ... + 1999590499.

It is an arithmetic number, because the mean of its divisors is an integer number (5998771485).

Almost surely, 2^19995904945 is an apocalyptic number.

It is an amenable number.

19995904945 is a deficient number, since it is larger than the sum of its proper divisors (3999180995).

19995904945 is an equidigital number, since it uses as much as digits as its factorization.

19995904945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3999180994.

The product of its (nonzero) digits is 23619600, while the sum is 64.

The spelling of 19995904945 in words is "nineteen billion, nine hundred ninety-five million, nine hundred four thousand, nine hundred forty-five".