17981021153 has 8 divisors (see below), whose sum is σ = 18143385000. Its totient is φ = 17818714368.

The previous prime is 17981021117. The next prime is 17981021197. The reversal of 17981021153 is 35112018971.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 22877089 + 17958144064 = 4783^2 + 134008^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 17981021153 - 2³⁴ = 801151969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17981021053) 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 7 ways as a sum of consecutive naturals, for example, 856223 + ... + 876971.

It is an arithmetic number, because the mean of its divisors is an integer number (2267923125).

Almost surely, 2^17981021153 is an apocalyptic number.

It is an amenable number.

17981021153 is a deficient number, since it is larger than the sum of its proper divisors (162363847).

17981021153 is a wasteful number, since it uses less digits than its factorization.

17981021153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28531.

The product of its (nonzero) digits is 15120, while the sum is 38.

The spelling of 17981021153 in words is "seventeen billion, nine hundred eighty-one million, twenty-one thousand, one hundred fifty-three".