40782421 has 2 divisors, whose sum is σ = 40782422. Its totient is φ = 40782420.

The previous prime is 40782419. The next prime is 40782451. The reversal of 40782421 is 12428704.

40782421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31203396 + 9579025 = 5586^2 + 3095^2 .

It is a cyclic number.

It is not a de Polignac number, because 40782421 - 2¹ = 40782419 is a prime.

Together with 40782419, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 40782421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40782451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20391210 + 20391211.

It is an arithmetic number, because the mean of its divisors is an integer number (20391211).

Almost surely, 2^40782421 is an apocalyptic number.

It is an amenable number.

40782421 is a deficient number, since it is larger than the sum of its proper divisors (1).

40782421 is an equidigital number, since it uses as much as digits as its factorization.

40782421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 40782421 is about 6386.1115712145. Note that the first 3 decimals coincide. The cubic root of 40782421 is about 344.2106746512.

It can be divided in two parts, 407 and 82421, that added together give a palindrome (82828).

The spelling of 40782421 in words is "forty million, seven hundred eighty-two thousand, four hundred twenty-one".