985021409 has 2 divisors, whose sum is σ = 985021410. Its totient is φ = 985021408.

The previous prime is 985021399. The next prime is 985021417. The reversal of 985021409 is 904120589.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 984202384 + 819025 = 31372^2 + 905^2 .

It is a cyclic number.

It is not a de Polignac number, because 985021409 - 2⁴ = 985021393 is a prime.

It is not a weakly prime, because it can be changed into another prime (985021459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492510704 + 492510705.

It is an arithmetic number, because the mean of its divisors is an integer number (492510705).

Almost surely, 2^985021409 is an apocalyptic number.

It is an amenable number.

985021409 is a deficient number, since it is larger than the sum of its proper divisors (1).

985021409 is an equidigital number, since it uses as much as digits as its factorization.

985021409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 985021409 is about 31385.0507248276. The cubic root of 985021409 is about 994.9819981087.

The spelling of 985021409 in words is "nine hundred eighty-five million, twenty-one thousand, four hundred nine".