21136241 has 16 divisors (see below), whose sum is σ = 25691904. Its totient is φ = 16995264.

The previous prime is 21136237. The next prime is 21136249. The reversal of 21136241 is 14263112.

It is a cyclic number.

It is not a de Polignac number, because 21136241 - 2² = 21136237 is a prime.

It is a super-2 number, since 2×21136241² = 893481367220162, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21136249) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7295 + ... + 9771.

It is an arithmetic number, because the mean of its divisors is an integer number (1605744).

Almost surely, 2^21136241 is an apocalyptic number.

It is an amenable number.

21136241 is a deficient number, since it is larger than the sum of its proper divisors (4555663).

21136241 is a wasteful number, since it uses less digits than its factorization.

21136241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560.

The product of its digits is 288, while the sum is 20.

The square root of 21136241 is about 4597.4167746681. The cubic root of 21136241 is about 276.4877646977.

Adding to 21136241 its reverse (14263112), we get a palindrome (35399353).

The spelling of 21136241 in words is "twenty-one million, one hundred thirty-six thousand, two hundred forty-one".