19234638721 has 9 divisors (see below), whose sum is σ = 19339080033. Its totient is φ = 19130760660.

The previous prime is 19234638701. The next prime is 19234638749. The reversal of 19234638721 is 12783643291.

The square root of 19234638721 is 138689.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 19234638721 - 2²¹ = 19232541569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19234638701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 45905850 + ... + 45906268.

Almost surely, 2^19234638721 is an apocalyptic number.

19234638721 is the 138689-th square number.

19234638721 is the 69345-th centered octagonal number.

It is an amenable number.

19234638721 is a deficient number, since it is larger than the sum of its proper divisors (104441312).

19234638721 is an frugal number, since it uses more digits than its factorization.

19234638721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1500 (or 750 counting only the distinct ones).

The product of its digits is 435456, while the sum is 46.

The spelling of 19234638721 in words is "nineteen billion, two hundred thirty-four million, six hundred thirty-eight thousand, seven hundred twenty-one".