1671998999 has 8 divisors (see below), whose sum is σ = 1825597440. Its totient is φ = 1518667000.

The previous prime is 1671998989. The next prime is 1671999001. The reversal of 1671998999 is 9998991761.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1671998999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671998929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53369 + ... + 78690.

It is an arithmetic number, because the mean of its divisors is an integer number (228199680).

Almost surely, 2^1671998999 is an apocalyptic number.

1671998999 is a deficient number, since it is larger than the sum of its proper divisors (153598441).

1671998999 is a wasteful number, since it uses less digits than its factorization.

1671998999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133221.

The product of its digits is 19840464, while the sum is 68.

The square root of 1671998999 is about 40890.0843603923. The cubic root of 1671998999 is about 1186.8941912216.

The spelling of 1671998999 in words is "one billion, six hundred seventy-one million, nine hundred ninety-eight thousand, nine hundred ninety-nine".