40021243 has 2 divisors, whose sum is σ = 40021244. Its totient is φ = 40021242.

The previous prime is 40021231. The next prime is 40021249. The reversal of 40021243 is 34212004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40021243 - 2⁵ = 40021211 is a prime.

It is not a weakly prime, because it can be changed into another prime (40021249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20010621 + 20010622.

It is an arithmetic number, because the mean of its divisors is an integer number (20010622).

Almost surely, 2^40021243 is an apocalyptic number.

40021243 is a deficient number, since it is larger than the sum of its proper divisors (1).

40021243 is an equidigital number, since it uses as much as digits as its factorization.

40021243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 40021243 is about 6326.2345040316. The cubic root of 40021243 is about 342.0557203195.

Adding to 40021243 its reverse (34212004), we get a palindrome (74233247).

The spelling of 40021243 in words is "forty million, twenty-one thousand, two hundred forty-three".