1989666971 has 8 divisors (see below), whose sum is σ = 2078078640. Its totient is φ = 1903078368.

The previous prime is 1989666937. The next prime is 1989666977. The reversal of 1989666971 is 1796669891.

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 1989666971 - 2²² = 1985472667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1989666977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 453536 + ... + 457901.

It is an arithmetic number, because the mean of its divisors is an integer number (259759830).

Almost surely, 2^1989666971 is an apocalyptic number.

1989666971 is a deficient number, since it is larger than the sum of its proper divisors (88411669).

1989666971 is an equidigital number, since it uses as much as digits as its factorization.

1989666971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911533.

The product of its digits is 8817984, while the sum is 62.

The square root of 1989666971 is about 44605.6831693003. The cubic root of 1989666971 is about 1257.7475022399.

The spelling of 1989666971 in words is "one billion, nine hundred eighty-nine million, six hundred sixty-six thousand, nine hundred seventy-one".