1002001199821 has 2 divisors, whose sum is σ = 1002001199822. Its totient is φ = 1002001199820.

The previous prime is 1002001199803. The next prime is 1002001199887. The reversal of 1002001199821 is 1289911002001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 901265422500 + 100735777321 = 949350^2 + 317389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1002001199821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1002001199021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501000599910 + 501000599911.

It is an arithmetic number, because the mean of its divisors is an integer number (501000599911).

Almost surely, 2^{1002001199821} is an apocalyptic number.

It is an amenable number.

1002001199821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002001199821 is an equidigital number, since it uses as much as digits as its factorization.

1002001199821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 34.

The spelling of 1002001199821 in words is "one trillion, two billion, one million, one hundred ninety-nine thousand, eight hundred twenty-one".