189915802081 has 4 divisors (see below), whose sum is σ = 189918639252. Its totient is φ = 189912964912.

The previous prime is 189915802033. The next prime is 189915802091. The reversal of 189915802081 is 180208519981.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 93220302400 + 96695499681 = 305320^2 + 310959^2 .

It is a cyclic number.

It is not a de Polignac number, because 189915802081 - 2¹⁷ = 189915671009 is a prime.

It is a super-2 number, since 2×189915802081² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189915802091) 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, 1315690 + ... + 1452883.

It is an arithmetic number, because the mean of its divisors is an integer number (47479659813).

Almost surely, 2^189915802081 is an apocalyptic number.

It is an amenable number.

189915802081 is a deficient number, since it is larger than the sum of its proper divisors (2837171).

189915802081 is an equidigital number, since it uses as much as digits as its factorization.

189915802081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2837170.

The product of its (nonzero) digits is 414720, while the sum is 52.

The spelling of 189915802081 in words is "one hundred eighty-nine billion, nine hundred fifteen million, eight hundred two thousand, eighty-one".