19992001 has 2 divisors, whose sum is σ = 19992002. Its totient is φ = 19992000.

The previous prime is 19991989. The next prime is 19992029. The reversal of 19992001 is 10029991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15992001 + 4000000 = 3999^2 + 2000^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19992001 is a prime.

It is not a weakly prime, because it can be changed into another prime (19992601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9996000 + 9996001.

It is an arithmetic number, because the mean of its divisors is an integer number (9996001).

Almost surely, 2^19992001 is an apocalyptic number.

It is an amenable number.

19992001 is a deficient number, since it is larger than the sum of its proper divisors (1).

19992001 is an equidigital number, since it uses as much as digits as its factorization.

19992001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 31.

The square root of 19992001 is about 4471.2415501737. The cubic root of 19992001 is about 271.4055691231.

The spelling of 19992001 in words is "nineteen million, nine hundred ninety-two thousand, one".