19797787 has 2 divisors, whose sum is σ = 19797788. Its totient is φ = 19797786.

The previous prime is 19797781. The next prime is 19797839. The reversal of 19797787 is 78779791.

It is a weak prime.

It is an emirp because it is prime and its reverse (78779791) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19797787 is a prime.

It is not a weakly prime, because it can be changed into another prime (19797781) 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, 9898893 + 9898894.

It is an arithmetic number, because the mean of its divisors is an integer number (9898894).

Almost surely, 2^19797787 is an apocalyptic number.

19797787 is a deficient number, since it is larger than the sum of its proper divisors (1).

19797787 is an equidigital number, since it uses as much as digits as its factorization.

19797787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1555848, while the sum is 55.

The square root of 19797787 is about 4449.4704179262. The cubic root of 19797787 is about 270.5238435413.

The spelling of 19797787 in words is "nineteen million, seven hundred ninety-seven thousand, seven hundred eighty-seven".