189816947 has 4 divisors (see below), whose sum is σ = 190076640. Its totient is φ = 189557256.

The previous prime is 189816941. The next prime is 189816961. The reversal of 189816947 is 749618981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 749618981 = 67 ⋅11188343.

It is a cyclic number.

It is not a de Polignac number, because 189816947 - 2¹⁸ = 189554803 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189816941) 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, 128747 + ... + 130212.

It is an arithmetic number, because the mean of its divisors is an integer number (47519160).

Almost surely, 2^189816947 is an apocalyptic number.

189816947 is a deficient number, since it is larger than the sum of its proper divisors (259693).

189816947 is an equidigital number, since it uses as much as digits as its factorization.

189816947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259692.

The product of its digits is 870912, while the sum is 53.

The square root of 189816947 is about 13777.4071218063. The cubic root of 189816947 is about 574.7050252635.

The spelling of 189816947 in words is "one hundred eighty-nine million, eight hundred sixteen thousand, nine hundred forty-seven".