189749973609 has 27 divisors (see below), whose sum is σ = 318846959613. Its totient is φ = 108423329112.

The previous prime is 189749973587. The next prime is 189749973659. The reversal of 189749973609 is 906379947981.

The square root of 189749973609 is 435603.

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

189749973609 is a `hidden beast` number, since 1 + 8 + 9 + 7 + 4 + 9 + 9 + 7 + 3 + 609 = 666.

It is not a de Polignac number, because 189749973609 - 2¹⁵ = 189749940841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (189749973659) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9137292 + ... + 9158034.

Almost surely, 2^189749973609 is an apocalyptic number.

189749973609 is the 435603-rd square number.

189749973609 is the 217802-nd centered octagonal number.

It is an amenable number.

189749973609 is a deficient number, since it is larger than the sum of its proper divisors (129096986004).

189749973609 is an frugal number, since it uses more digits than its factorization.

189749973609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41506 (or 20753 counting only the distinct ones).

The product of its (nonzero) digits is 185177664, while the sum is 72.

The spelling of 189749973609 in words is "one hundred eighty-nine billion, seven hundred forty-nine million, nine hundred seventy-three thousand, six hundred nine".