21740241 has 16 divisors (see below), whose sum is σ = 29917184. Its totient is φ = 14034384.

The previous prime is 21740239. The next prime is 21740249. The reversal of 21740241 is 14204712.

It is a happy number.

It is not a de Polignac number, because 21740241 - 2¹ = 21740239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21740249) 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, 15720 + ... + 17046.

It is an arithmetic number, because the mean of its divisors is an integer number (1869824).

Almost surely, 2^21740241 is an apocalyptic number.

It is an amenable number.

21740241 is a deficient number, since it is larger than the sum of its proper divisors (8176943).

21740241 is a wasteful number, since it uses less digits than its factorization.

21740241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1500.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 21740241 is about 4662.6431345322. The cubic root of 21740241 is about 279.0967534836.

Adding to 21740241 its reverse (14204712), we get a palindrome (35944953).

The spelling of 21740241 in words is "twenty-one million, seven hundred forty thousand, two hundred forty-one".