1000090991021 has 2 divisors, whose sum is σ = 1000090991022. Its totient is φ = 1000090991020.

The previous prime is 1000090990963. The next prime is 1000090991033. The reversal of 1000090991021 is 1201990900001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 789634840996 + 210456150025 = 888614^2 + 458755^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1000090991021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1000090991071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500045495510 + 500045495511.

It is an arithmetic number, because the mean of its divisors is an integer number (500045495511).

Almost surely, 2^{1000090991021} is an apocalyptic number.

It is an amenable number.

1000090991021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000090991021 is an equidigital number, since it uses as much as digits as its factorization.

1000090991021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 32.

The spelling of 1000090991021 in words is "one trillion, ninety million, nine hundred ninety-one thousand, twenty-one".