21544901 has 8 divisors (see below), whose sum is σ = 24766464. Its totient is φ = 18359280.

The previous prime is 21544889. The next prime is 21544903. The reversal of 21544901 is 10944512.

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 21544901 - 2¹⁰ = 21543877 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 (21544903) 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, 7685 + ... + 10106.

It is an arithmetic number, because the mean of its divisors is an integer number (3095808).

Almost surely, 2^21544901 is an apocalyptic number.

It is an amenable number.

21544901 is a deficient number, since it is larger than the sum of its proper divisors (3221563).

21544901 is a wasteful number, since it uses less digits than its factorization.

21544901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17971.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 21544901 is about 4641.6485218077. The cubic root of 21544901 is about 278.2583256911.

The spelling of 21544901 in words is "twenty-one million, five hundred forty-four thousand, nine hundred one".