21752241 has 16 divisors (see below), whose sum is σ = 33247104. Its totient is φ = 12392064.

The previous prime is 21752239. The next prime is 21752243. The reversal of 21752241 is 14225712.

It is an interprime number because it is at equal distance from previous prime (21752239) and next prime (21752243).

It is not a de Polignac number, because 21752241 - 2¹ = 21752239 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21752243) 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, 6445 + ... + 9221.

It is an arithmetic number, because the mean of its divisors is an integer number (2077944).

Almost surely, 2^21752241 is an apocalyptic number.

21752241 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21752241 is a deficient number, since it is larger than the sum of its proper divisors (11494863).

21752241 is a wasteful number, since it uses less digits than its factorization.

21752241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3160.

The product of its digits is 1120, while the sum is 24.

The square root of 21752241 is about 4663.9297807750. The cubic root of 21752241 is about 279.1480952176.

Adding to 21752241 its reverse (14225712), we get a palindrome (35977953).

The spelling of 21752241 in words is "twenty-one million, seven hundred fifty-two thousand, two hundred forty-one".