19694784545 has 4 divisors (see below), whose sum is σ = 23633741460. Its totient is φ = 15755827632.

The previous prime is 19694784541. The next prime is 19694784547. The reversal of 19694784545 is 54548749691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54548749691 = 15193 ⋅3590387.

It can be written as a sum of positive squares in 2 ways, for example, as 13580639296 + 6114145249 = 116536^2 + 78193^2 .

It is a cyclic number.

It is not a de Polignac number, because 19694784545 - 2² = 19694784541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19694784541) 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, 1969478450 + ... + 1969478459.

It is an arithmetic number, because the mean of its divisors is an integer number (5908435365).

Almost surely, 2^19694784545 is an apocalyptic number.

It is an amenable number.

19694784545 is a deficient number, since it is larger than the sum of its proper divisors (3938956915).

19694784545 is an equidigital number, since it uses as much as digits as its factorization.

19694784545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3938956914.

The product of its digits is 43545600, while the sum is 62.

The spelling of 19694784545 in words is "nineteen billion, six hundred ninety-four million, seven hundred eighty-four thousand, five hundred forty-five".