19899437 has 2 divisors, whose sum is σ = 19899438. Its totient is φ = 19899436.

The previous prime is 19899353. The next prime is 19899443. The reversal of 19899437 is 73499891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16491721 + 3407716 = 4061^2 + 1846^2 .

It is a cyclic number.

It is not a de Polignac number, because 19899437 - 2¹² = 19895341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19899457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949718 + 9949719.

It is an arithmetic number, because the mean of its divisors is an integer number (9949719).

Almost surely, 2^19899437 is an apocalyptic number.

It is an amenable number.

19899437 is a deficient number, since it is larger than the sum of its proper divisors (1).

19899437 is an equidigital number, since it uses as much as digits as its factorization.

19899437 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 50.

The square root of 19899437 is about 4460.8785009233. The cubic root of 19899437 is about 270.9860470388.

The spelling of 19899437 in words is "nineteen million, eight hundred ninety-nine thousand, four hundred thirty-seven".