19897533 has 6 divisors (see below), whose sum is σ = 28740894. Its totient is φ = 13265016.

The previous prime is 19897489. The next prime is 19897543. The reversal of 19897533 is 33579891.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19027044 + 870489 = 4362^2 + 933^2 .

It is not a de Polignac number, because 19897533 - 2¹⁰ = 19896509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19897543) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1105410 + ... + 1105427.

It is an arithmetic number, because the mean of its divisors is an integer number (4790149).

Almost surely, 2^19897533 is an apocalyptic number.

It is an amenable number.

19897533 is a deficient number, since it is larger than the sum of its proper divisors (8843361).

19897533 is a wasteful number, since it uses less digits than its factorization.

19897533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210843 (or 2210840 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 19897533 is about 4460.6650849397. The cubic root of 19897533 is about 270.9774040155.

The spelling of 19897533 in words is "nineteen million, eight hundred ninety-seven thousand, five hundred thirty-three".