189149781 has 8 divisors (see below), whose sum is σ = 252763200. Its totient is φ = 125818112.

The previous prime is 189149773. The next prime is 189149797. The reversal of 189149781 is 187941981.

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 189149781 - 2³ = 189149773 is a prime.

It is a super-2 number, since 2×189149781² = 71555279304695922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 189149781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189149881) 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 7 ways as a sum of consecutive naturals, for example, 68865 + ... + 71558.

It is an arithmetic number, because the mean of its divisors is an integer number (31595400).

Almost surely, 2^189149781 is an apocalyptic number.

It is an amenable number.

189149781 is a deficient number, since it is larger than the sum of its proper divisors (63613419).

189149781 is a wasteful number, since it uses less digits than its factorization.

189149781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140875.

The product of its digits is 145152, while the sum is 48.

The square root of 189149781 is about 13753.1734883262. The cubic root of 189149781 is about 574.0309130806.

The spelling of 189149781 in words is "one hundred eighty-nine million, one hundred forty-nine thousand, seven hundred eighty-one".