19649689 has 2 divisors, whose sum is σ = 19649690. Its totient is φ = 19649688.

The previous prime is 19649681. The next prime is 19649717. The reversal of 19649689 is 98694691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16646400 + 3003289 = 4080^2 + 1733^2 .

It is a cyclic number.

It is not a de Polignac number, because 19649689 - 2³ = 19649681 is a prime.

It is a super-2 number, since 2×19649689² = 772220555593442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19649681) 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, 9824844 + 9824845.

It is an arithmetic number, because the mean of its divisors is an integer number (9824845).

Almost surely, 2^19649689 is an apocalyptic number.

It is an amenable number.

19649689 is a deficient number, since it is larger than the sum of its proper divisors (1).

19649689 is an equidigital number, since it uses as much as digits as its factorization.

19649689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 52.

The square root of 19649689 is about 4432.7969725671. The cubic root of 19649689 is about 269.8476003235.

The spelling of 19649689 in words is "nineteen million, six hundred forty-nine thousand, six hundred eighty-nine".