21258941 has 4 divisors (see below), whose sum is σ = 23191584. Its totient is φ = 19326300.

The previous prime is 21258917. The next prime is 21258973. The reversal of 21258941 is 14985212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21258941 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21258898 and 21258907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 966305 + ... + 966326.

It is an arithmetic number, because the mean of its divisors is an integer number (5797896).

Almost surely, 2^21258941 is an apocalyptic number.

It is an amenable number.

21258941 is a deficient number, since it is larger than the sum of its proper divisors (1932643).

21258941 is a wasteful number, since it uses less digits than its factorization.

21258941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932642.

The product of its digits is 5760, while the sum is 32.

The square root of 21258941 is about 4610.7419142693. The cubic root of 21258941 is about 277.0217545157.

The spelling of 21258941 in words is "twenty-one million, two hundred fifty-eight thousand, nine hundred forty-one".