189805729 has 9 divisors (see below), whose sum is σ = 198748753. Its totient is φ = 181250212.

The previous prime is 189805717. The next prime is 189805747. The reversal of 189805729 is 927508981.

The square root of 189805729 is 13777.

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

It is a de Polignac number, because none of the positive numbers 2^k-189805729 is a prime.

It is a super-2 number, since 2×189805729² = 72052429522442882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189805229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 316572 + ... + 317170.

Almost surely, 2^189805729 is an apocalyptic number.

189805729 is the 13777-th square number.

189805729 is the 6889-th centered octagonal number.

It is an amenable number.

189805729 is a deficient number, since it is larger than the sum of its proper divisors (8943024).

189805729 is an frugal number, since it uses more digits than its factorization.

189805729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1244 (or 622 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 49.

The cubic root of 189805729 is about 574.6937035347.

Multiplying 189805729 by its sum of digits (49), we get a square (9300480721 = 96439²).

The spelling of 189805729 in words is "one hundred eighty-nine million, eight hundred five thousand, seven hundred twenty-nine".