189991633 has 8 divisors (see below), whose sum is σ = 210136808. Its totient is φ = 170636544.

The previous prime is 189991597. The next prime is 189991639. The reversal of 189991633 is 336199981.

It can be written as a sum of positive squares in 4 ways, for example, as 58476609 + 131515024 = 7647^2 + 11468^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 189991633 - 2⁹ = 189991121 is a prime.

It is a super-2 number, since 2×189991633² = 72193641220013378, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189991639) 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, 197016 + ... + 197977.

It is an arithmetic number, because the mean of its divisors is an integer number (26267101).

Almost surely, 2^189991633 is an apocalyptic number.

189991633 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

189991633 is a deficient number, since it is larger than the sum of its proper divisors (20145175).

189991633 is a wasteful number, since it uses less digits than its factorization.

189991633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395043.

The product of its digits is 314928, while the sum is 49.

The square root of 189991633 is about 13783.7452457596. The cubic root of 189991633 is about 574.8812689948.

The spelling of 189991633 in words is "one hundred eighty-nine million, nine hundred ninety-one thousand, six hundred thirty-three".