19723969 has 2 divisors, whose sum is σ = 19723970. Its totient is φ = 19723968.

The previous prime is 19723939. The next prime is 19724011. The reversal of 19723969 is 96932791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18378369 + 1345600 = 4287^2 + 1160^2 .

It is a cyclic number.

It is not a de Polignac number, because 19723969 - 2⁷ = 19723841 is a prime.

It is a super-2 number, since 2×19723969² = 778069906225922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19723939) 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, 9861984 + 9861985.

It is an arithmetic number, because the mean of its divisors is an integer number (9861985).

Almost surely, 2^19723969 is an apocalyptic number.

It is an amenable number.

19723969 is a deficient number, since it is larger than the sum of its proper divisors (1).

19723969 is an equidigital number, since it uses as much as digits as its factorization.

19723969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 46.

The square root of 19723969 is about 4441.1675266758. The cubic root of 19723969 is about 270.1871998536.

The spelling of 19723969 in words is "nineteen million, seven hundred twenty-three thousand, nine hundred sixty-nine".