21097533 has 8 divisors (see below), whose sum is σ = 28152000. Its totient is φ = 14054048.

The previous prime is 21097513. The next prime is 21097547. The reversal of 21097533 is 33579012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21097533 - 2⁶ = 21097469 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21097533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21097513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4393 + ... + 7841.

It is an arithmetic number, because the mean of its divisors is an integer number (3519000).

Almost surely, 2^21097533 is an apocalyptic number.

It is an amenable number.

21097533 is a deficient number, since it is larger than the sum of its proper divisors (7054467).

21097533 is a wasteful number, since it uses less digits than its factorization.

21097533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5491.

The product of its (nonzero) digits is 5670, while the sum is 30.

The square root of 21097533 is about 4593.2050901304. The cubic root of 21097533 is about 276.3188789706.

The spelling of 21097533 in words is "twenty-one million, ninety-seven thousand, five hundred thirty-three".