1001009003921 has 2 divisors, whose sum is σ = 1001009003922. Its totient is φ = 1001009003920.

The previous prime is 1001009003903. The next prime is 1001009003971. The reversal of 1001009003921 is 1293009001001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 750148264321 + 250860739600 = 866111^2 + 500860^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001009003921 - 2⁶ = 1001009003857 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001009003971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500504501960 + 500504501961.

It is an arithmetic number, because the mean of its divisors is an integer number (500504501961).

Almost surely, 2^{1001009003921} is an apocalyptic number.

It is an amenable number.

1001009003921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001009003921 is an equidigital number, since it uses as much as digits as its factorization.

1001009003921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 26.

The spelling of 1001009003921 in words is "one trillion, one billion, nine million, three thousand, nine hundred twenty-one".