21257041 has 8 divisors (see below), whose sum is σ = 23631104. Its totient is φ = 18988560.

The previous prime is 21257017. The next prime is 21257053. The reversal of 21257041 is 14075212.

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 21257041 - 2¹¹ = 21254993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21257011) 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, 25971 + ... + 26776.

It is an arithmetic number, because the mean of its divisors is an integer number (2953888).

Almost surely, 2^21257041 is an apocalyptic number.

It is an amenable number.

21257041 is a deficient number, since it is larger than the sum of its proper divisors (2374063).

21257041 is a wasteful number, since it uses less digits than its factorization.

21257041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52791.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21257041 is about 4610.5358690721. The cubic root of 21257041 is about 277.0135014076.

The spelling of 21257041 in words is "twenty-one million, two hundred fifty-seven thousand, forty-one".