21356241 has 8 divisors (see below), whose sum is σ = 29393664. Its totient is φ = 13778160.

The previous prime is 21356219. The next prime is 21356287. The reversal of 21356241 is 14265312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21356241 - 2⁶ = 21356177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21356201) 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, 114726 + ... + 114911.

It is an arithmetic number, because the mean of its divisors is an integer number (3674208).

Almost surely, 2^21356241 is an apocalyptic number.

It is an amenable number.

21356241 is a deficient number, since it is larger than the sum of its proper divisors (8037423).

21356241 is a wasteful number, since it uses less digits than its factorization.

21356241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229671.

The product of its digits is 1440, while the sum is 24.

The square root of 21356241 is about 4621.2813158257. The cubic root of 21356241 is about 277.4437447853.

The spelling of 21356241 in words is "twenty-one million, three hundred fifty-six thousand, two hundred forty-one".