43740121 has 2 divisors, whose sum is σ = 43740122. Its totient is φ = 43740120.

The previous prime is 43740077. The next prime is 43740131. The reversal of 43740121 is 12104734.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27248400 + 16491721 = 5220^2 + 4061^2 .

It is a cyclic number.

It is not a de Polignac number, because 43740121 - 2¹¹ = 43738073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 43740092 and 43740101.

It is not a weakly prime, because it can be changed into another prime (43740131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21870060 + 21870061.

It is an arithmetic number, because the mean of its divisors is an integer number (21870061).

Almost surely, 2^43740121 is an apocalyptic number.

It is an amenable number.

43740121 is a deficient number, since it is larger than the sum of its proper divisors (1).

43740121 is an equidigital number, since it uses as much as digits as its factorization.

43740121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 43740121 is about 6613.6314532940. The cubic root of 43740121 is about 352.3384126013.

Adding to 43740121 its reverse (12104734), we get a palindrome (55844855).

The spelling of 43740121 in words is "forty-three million, seven hundred forty thousand, one hundred twenty-one".