19897231 has 16 divisors (see below), whose sum is σ = 21625344. Its totient is φ = 18257184.

The previous prime is 19897223. The next prime is 19897271. The reversal of 19897231 is 13279891.

It is a cyclic number.

It is not a de Polignac number, because 19897231 - 2³ = 19897223 is a prime.

It is a super-2 number, since 2×19897231² = 791799602934722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19897271) 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, 87540 + ... + 87766.

It is an arithmetic number, because the mean of its divisors is an integer number (1351584).

Almost surely, 2^19897231 is an apocalyptic number.

19897231 is a deficient number, since it is larger than the sum of its proper divisors (1728113).

19897231 is a wasteful number, since it uses less digits than its factorization.

19897231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390.

The product of its digits is 27216, while the sum is 40.

The square root of 19897231 is about 4460.6312333570. The cubic root of 19897231 is about 270.9760330652.

The spelling of 19897231 in words is "nineteen million, eight hundred ninety-seven thousand, two hundred thirty-one".