17889054921 has 6 divisors (see below), whose sum is σ = 25839746010. Its totient is φ = 11926036608.

The previous prime is 17889054881. The next prime is 17889054923. The reversal of 17889054921 is 12945098871.

It is a happy number.

17889054921 is a `hidden beast` number, since 1 + 7 + 8 + 8 + 90 + 549 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14074263225 + 3814791696 = 118635^2 + 61764^2 .

It is not a de Polignac number, because 17889054921 - 2²¹ = 17886957769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (17889054923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 993836376 + ... + 993836393.

It is an arithmetic number, because the mean of its divisors is an integer number (4306624335).

Almost surely, 2^17889054921 is an apocalyptic number.

It is an amenable number.

17889054921 is a deficient number, since it is larger than the sum of its proper divisors (7950691089).

17889054921 is a wasteful number, since it uses less digits than its factorization.

17889054921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1987672775 (or 1987672772 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 17889054921 in words is "seventeen billion, eight hundred eighty-nine million, fifty-four thousand, nine hundred twenty-one".