1002021689 has 2 divisors, whose sum is σ = 1002021690. Its totient is φ = 1002021688.

The previous prime is 1002021641. The next prime is 1002021731. The reversal of 1002021689 is 9861202001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 955304464 + 46717225 = 30908^2 + 6835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1002021689 is a prime.

It is not a weakly prime, because it can be changed into another prime (1002021989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501010844 + 501010845.

It is an arithmetic number, because the mean of its divisors is an integer number (501010845).

Almost surely, 2^1002021689 is an apocalyptic number.

It is an amenable number.

1002021689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002021689 is an equidigital number, since it uses as much as digits as its factorization.

1002021689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1002021689 is about 31654.7261716161. The cubic root of 1002021689 is about 1000.6734427064.

The spelling of 1002021689 in words is "one billion, two million, twenty-one thousand, six hundred eighty-nine".