1008891661 has 2 divisors, whose sum is σ = 1008891662. Its totient is φ = 1008891660.

The previous prime is 1008891649. The next prime is 1008891713. The reversal of 1008891661 is 1661988001.

1008891661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 804573225 + 204318436 = 28365^2 + 14294^2 .

It is a cyclic number.

It is not a de Polignac number, because 1008891661 - 2²⁵ = 975337229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1008891601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 504445830 + 504445831.

It is an arithmetic number, because the mean of its divisors is an integer number (504445831).

Almost surely, 2^1008891661 is an apocalyptic number.

It is an amenable number.

1008891661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1008891661 is an equidigital number, since it uses as much as digits as its factorization.

1008891661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 1008891661 is about 31763.0549695712. The cubic root of 1008891661 is about 1002.9551455127.

The spelling of 1008891661 in words is "one billion, eight million, eight hundred ninety-one thousand, six hundred sixty-one".