21154043 has 8 divisors (see below), whose sum is σ = 22223616. Its totient is φ = 20097000.

The previous prime is 21154039. The next prime is 21154097. The reversal of 21154043 is 34045112.

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 21154043 - 2² = 21154039 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154943) 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, 428 + ... + 6518.

It is an arithmetic number, because the mean of its divisors is an integer number (2777952).

Almost surely, 2^21154043 is an apocalyptic number.

21154043 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21154043 is a deficient number, since it is larger than the sum of its proper divisors (1069573).

21154043 is a wasteful number, since it uses less digits than its factorization.

21154043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6265.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21154043 is about 4599.3524544223. The cubic root of 21154043 is about 276.5653668593.

Adding to 21154043 its reverse (34045112), we get a palindrome (55199155).

The spelling of 21154043 in words is "twenty-one million, one hundred fifty-four thousand, forty-three".