21054549 has 24 divisors (see below), whose sum is σ = 29710560. Its totient is φ = 13258080.

The previous prime is 21054541. The next prime is 21054559. The reversal of 21054549 is 94545012.

It is not a de Polignac number, because 21054549 - 2³ = 21054541 is a prime.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

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

It is a Curzon number.

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 23 ways as a sum of consecutive naturals, for example, 193107 + ... + 193215.

It is an arithmetic number, because the mean of its divisors is an integer number (1237940).

Almost surely, 2^21054549 is an apocalyptic number.

It is an amenable number.

21054549 is a deficient number, since it is larger than the sum of its proper divisors (8656011).

21054549 is a wasteful number, since it uses less digits than its factorization.

21054549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 21054549 is about 4588.5236187689. The cubic root of 21054549 is about 276.1310945176.

The spelling of 21054549 in words is "twenty-one million, fifty-four thousand, five hundred forty-nine".