19897699 has 2 divisors, whose sum is σ = 19897700. Its totient is φ = 19897698.

The previous prime is 19897663. The next prime is 19897729. The reversal of 19897699 is 99679891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19897699 - 2⁷ = 19897571 is a prime.

It is not a weakly prime, because it can be changed into another prime (19877699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9948849 + 9948850.

It is an arithmetic number, because the mean of its divisors is an integer number (9948850).

Almost surely, 2^19897699 is an apocalyptic number.

19897699 is a deficient number, since it is larger than the sum of its proper divisors (1).

19897699 is an equidigital number, since it uses as much as digits as its factorization.

19897699 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2204496, while the sum is 58.

The square root of 19897699 is about 4460.6836919916. The cubic root of 19897699 is about 270.9781575784.

The spelling of 19897699 in words is "nineteen million, eight hundred ninety-seven thousand, six hundred ninety-nine".