189897647 has 4 divisors (see below), whose sum is σ = 199892280. Its totient is φ = 179903016.

The previous prime is 189897641. The next prime is 189897649. The reversal of 189897647 is 746798981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 746798981 = 29 ⋅25751689.

It is a cyclic number.

It is not a de Polignac number, because 189897647 - 2⁸ = 189897391 is a prime.

It is a super-2 number, since 2×189897647² = 72122232672273218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189897641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4997288 + ... + 4997325.

It is an arithmetic number, because the mean of its divisors is an integer number (49973070).

Almost surely, 2^189897647 is an apocalyptic number.

189897647 is a deficient number, since it is larger than the sum of its proper divisors (9994633).

189897647 is an equidigital number, since it uses as much as digits as its factorization.

189897647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9994632.

The product of its digits is 6096384, while the sum is 59.

The square root of 189897647 is about 13780.3355184117. The cubic root of 189897647 is about 574.7864583235.

The spelling of 189897647 in words is "one hundred eighty-nine million, eight hundred ninety-seven thousand, six hundred forty-seven".