19956749 has 2 divisors, whose sum is σ = 19956750. Its totient is φ = 19956748.

The previous prime is 19956697. The next prime is 19956757. The reversal of 19956749 is 94765991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16752649 + 3204100 = 4093^2 + 1790^2 .

It is a cyclic number.

It is not a de Polignac number, because 19956749 - 2¹⁶ = 19891213 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 19956697 and 19956706.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19956799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9978374 + 9978375.

It is an arithmetic number, because the mean of its divisors is an integer number (9978375).

Almost surely, 2^19956749 is an apocalyptic number.

It is an amenable number.

19956749 is a deficient number, since it is larger than the sum of its proper divisors (1).

19956749 is an equidigital number, since it uses as much as digits as its factorization.

19956749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 612360, while the sum is 50.

The square root of 19956749 is about 4467.2977290528. The cubic root of 19956749 is about 271.2459516480.

The spelling of 19956749 in words is "nineteen million, nine hundred fifty-six thousand, seven hundred forty-nine".