21154573 has 8 divisors (see below), whose sum is σ = 23234400. Its totient is φ = 19100880.

The previous prime is 21154547. The next prime is 21154577. The reversal of 21154573 is 37545112.

It is a happy number.

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 21154573 - 2¹⁷ = 21023501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4815 + ... + 8092.

It is an arithmetic number, because the mean of its divisors is an integer number (2904300).

Almost surely, 2^21154573 is an apocalyptic number.

It is an amenable number.

21154573 is a deficient number, since it is larger than the sum of its proper divisors (2079827).

21154573 is a wasteful number, since it uses less digits than its factorization.

21154573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13067.

The product of its digits is 4200, while the sum is 28.

The square root of 21154573 is about 4599.4100708678. The cubic root of 21154573 is about 276.5676765584.

Adding to 21154573 its reverse (37545112), we get a palindrome (58699685).

The spelling of 21154573 in words is "twenty-one million, one hundred fifty-four thousand, five hundred seventy-three".