19897197 has 16 divisors (see below), whose sum is σ = 26972352. Its totient is φ = 13045760.

The previous prime is 19897193. The next prime is 19897223. The reversal of 19897197 is 79179891.

It is a cyclic number.

It is not a de Polignac number, because 19897197 - 2² = 19897193 is a prime.

Its product of digits (285768) is a multiple of the sum of its prime divisors (588).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19897193) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77293 + ... + 77549.

It is an arithmetic number, because the mean of its divisors is an integer number (1685772).

Almost surely, 2^19897197 is an apocalyptic number.

It is an amenable number.

19897197 is a deficient number, since it is larger than the sum of its proper divisors (7075155).

19897197 is a wasteful number, since it uses less digits than its factorization.

19897197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588.

The product of its digits is 285768, while the sum is 51.

The square root of 19897197 is about 4460.6274222356. The cubic root of 19897197 is about 270.9758787189.

The spelling of 19897197 in words is "nineteen million, eight hundred ninety-seven thousand, one hundred ninety-seven".