981000191 has 4 divisors (see below), whose sum is σ = 1032631800. Its totient is φ = 929368584.

The previous prime is 981000103. The next prime is 981000199. The reversal of 981000191 is 191000189.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 981000191 - 2¹⁴ = 980983807 is a prime.

It is a super-2 number, since 2×981000191² = 1924722749484072962, 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 (981000199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25815776 + ... + 25815813.

It is an arithmetic number, because the mean of its divisors is an integer number (258157950).

Almost surely, 2^981000191 is an apocalyptic number.

981000191 is a deficient number, since it is larger than the sum of its proper divisors (51631609).

981000191 is a wasteful number, since it uses less digits than its factorization.

981000191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51631608.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 981000191 is about 31320.9225758118. The cubic root of 981000191 is about 993.6261912077.

The spelling of 981000191 in words is "nine hundred eighty-one million, one hundred ninety-one", and thus it is an aban number.