21532393 has 16 divisors (see below), whose sum is σ = 23207040. Its totient is φ = 19933056.

The previous prime is 21532373. The next prime is 21532403. The reversal of 21532393 is 39323512.

It is a cyclic number.

It is not a de Polignac number, because 21532393 - 2⁵ = 21532361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21532333) 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, 137071 + ... + 137227.

It is an arithmetic number, because the mean of its divisors is an integer number (1450440).

Almost surely, 2^21532393 is an apocalyptic number.

21532393 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21532393 is a deficient number, since it is larger than the sum of its proper divisors (1674647).

21532393 is a wasteful number, since it uses less digits than its factorization.

21532393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336.

The product of its digits is 4860, while the sum is 28.

The square root of 21532393 is about 4640.3009600671. The cubic root of 21532393 is about 278.2044671797.

The spelling of 21532393 in words is "twenty-one million, five hundred thirty-two thousand, three hundred ninety-three".