24240721 has 2 divisors, whose sum is σ = 24240722. Its totient is φ = 24240720.

The previous prime is 24240719. The next prime is 24240737. The reversal of 24240721 is 12704242.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12680721 + 11560000 = 3561^2 + 3400^2 .

It is a cyclic number.

It is not a de Polignac number, because 24240721 - 2¹ = 24240719 is a prime.

It is a super-2 number, since 2×24240721² = 1175225109199682, which contains 22 as substring.

Together with 24240719, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 24240692 and 24240701.

It is not a weakly prime, because it can be changed into another prime (24240761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12120360 + 12120361.

It is an arithmetic number, because the mean of its divisors is an integer number (12120361).

Almost surely, 2^24240721 is an apocalyptic number.

It is an amenable number.

24240721 is a deficient number, since it is larger than the sum of its proper divisors (1).

24240721 is an equidigital number, since it uses as much as digits as its factorization.

24240721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 24240721 is about 4923.4866710493. The cubic root of 24240721 is about 289.4110958430.

Adding to 24240721 its reverse (12704242), we get a palindrome (36944963).

The spelling of 24240721 in words is "twenty-four million, two hundred forty thousand, seven hundred twenty-one".