21054543 has 8 divisors (see below), whose sum is σ = 28670208. Its totient is φ = 13737624.

The previous prime is 21054541. The next prime is 21054559. The reversal of 21054543 is 34545012.

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

It is not a de Polignac number, because 21054543 - 2¹ = 21054541 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74521 + ... + 74802.

It is an arithmetic number, because the mean of its divisors is an integer number (3583776).

Almost surely, 2^21054543 is an apocalyptic number.

21054543 is a deficient number, since it is larger than the sum of its proper divisors (7615665).

21054543 is a wasteful number, since it uses less digits than its factorization.

21054543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149373.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21054543 is about 4588.5229649638. The cubic root of 21054543 is about 276.1310682876.

Adding to 21054543 its reverse (34545012), we get a palindrome (55599555).

The spelling of 21054543 in words is "twenty-one million, fifty-four thousand, five hundred forty-three".