1690099721 has 2 divisors, whose sum is σ = 1690099722. Its totient is φ = 1690099720.

The previous prime is 1690099703. The next prime is 1690099771. The reversal of 1690099721 is 1279900961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 953574400 + 736525321 = 30880^2 + 27139^2 .

It is a cyclic number.

It is not a de Polignac number, because 1690099721 - 2³⁰ = 616357897 is a prime.

It is not a weakly prime, because it can be changed into another prime (1690099771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845049860 + 845049861.

It is an arithmetic number, because the mean of its divisors is an integer number (845049861).

Almost surely, 2^1690099721 is an apocalyptic number.

It is an amenable number.

1690099721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1690099721 is an equidigital number, since it uses as much as digits as its factorization.

1690099721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 61236, while the sum is 44.

The square root of 1690099721 is about 41110.8224315690. The cubic root of 1690099721 is about 1191.1618530423.

The spelling of 1690099721 in words is "one billion, six hundred ninety million, ninety-nine thousand, seven hundred twenty-one".