19673681 has 2 divisors, whose sum is σ = 19673682. Its totient is φ = 19673680.

The previous prime is 19673651. The next prime is 19673699. The reversal of 19673681 is 18637691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15673681 + 4000000 = 3959^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 19673681 - 2⁶ = 19673617 is a prime.

It is a super-2 number, since 2×19673681² = 774107448179522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19673651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9836840 + 9836841.

It is an arithmetic number, because the mean of its divisors is an integer number (9836841).

Almost surely, 2^19673681 is an apocalyptic number.

It is an amenable number.

19673681 is a deficient number, since it is larger than the sum of its proper divisors (1).

19673681 is an equidigital number, since it uses as much as digits as its factorization.

19673681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 19673681 is about 4435.5023390818. The cubic root of 19673681 is about 269.9573823910.

The spelling of 19673681 in words is "nineteen million, six hundred seventy-three thousand, six hundred eighty-one".