19181532644 has 24 divisors (see below), whose sum is σ = 34076763840. Its totient is φ = 9445382496.

The previous prime is 19181532641. The next prime is 19181532653. The reversal of 19181532644 is 44623518191.

It is a junction number, because it is equal to n+sod(n) for n = 19181532595 and 19181532604.

It is not an unprimeable number, because it can be changed into a prime (19181532641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2119922 + ... + 2128950.

It is an arithmetic number, because the mean of its divisors is an integer number (1419865160).

Almost surely, 2^19181532644 is an apocalyptic number.

It is an amenable number.

19181532644 is a deficient number, since it is larger than the sum of its proper divisors (14895231196).

19181532644 is a wasteful number, since it uses less digits than its factorization.

19181532644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17027 (or 17025 counting only the distinct ones).

The product of its digits is 207360, while the sum is 44.

The spelling of 19181532644 in words is "nineteen billion, one hundred eighty-one million, five hundred thirty-two thousand, six hundred forty-four".