19678949 has 2 divisors, whose sum is σ = 19678950. Its totient is φ = 19678948.

The previous prime is 19678933. The next prime is 19678963. The reversal of 19678949 is 94987691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17556100 + 2122849 = 4190^2 + 1457^2 .

It is a cyclic number.

It is not a de Polignac number, because 19678949 - 2⁴ = 19678933 is a prime.

It is a super-2 number, since 2×19678949² = 774522067489202, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19678949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19678909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9839474 + 9839475.

It is an arithmetic number, because the mean of its divisors is an integer number (9839475).

Almost surely, 2^19678949 is an apocalyptic number.

It is an amenable number.

19678949 is a deficient number, since it is larger than the sum of its proper divisors (1).

19678949 is an equidigital number, since it uses as much as digits as its factorization.

19678949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 53.

The square root of 19678949 is about 4436.0961441339. The cubic root of 19678949 is about 269.9814756381.

The spelling of 19678949 in words is "nineteen million, six hundred seventy-eight thousand, nine hundred forty-nine".