19699997 has 2 divisors, whose sum is σ = 19699998. Its totient is φ = 19699996.

The previous prime is 19699987. The next prime is 19700027. The reversal of 19699997 is 79999691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11062276 + 8637721 = 3326^2 + 2939^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19699997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19699987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9849998 + 9849999.

It is an arithmetic number, because the mean of its divisors is an integer number (9849999).

Almost surely, 2^19699997 is an apocalyptic number.

It is an amenable number.

19699997 is a deficient number, since it is larger than the sum of its proper divisors (1).

19699997 is an equidigital number, since it uses as much as digits as its factorization.

19699997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2480058, while the sum is 59.

The square root of 19699997 is about 4438.4678662800. The cubic root of 19699997 is about 270.0776959755.

The spelling of 19699997 in words is "nineteen million, six hundred ninety-nine thousand, nine hundred ninety-seven".