42782521 has 2 divisors, whose sum is σ = 42782522. Its totient is φ = 42782520.

The previous prime is 42782513. The next prime is 42782527. The reversal of 42782521 is 12528724.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29822521 + 12960000 = 5461^2 + 3600^2 .

It is a cyclic number.

It is not a de Polignac number, because 42782521 - 2³ = 42782513 is a prime.

It is not a weakly prime, because it can be changed into another prime (42782527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21391260 + 21391261.

It is an arithmetic number, because the mean of its divisors is an integer number (21391261).

Almost surely, 2^42782521 is an apocalyptic number.

It is an amenable number.

42782521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42782521 is an equidigital number, since it uses as much as digits as its factorization.

42782521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8960, while the sum is 31.

The square root of 42782521 is about 6540.8348855479. The cubic root of 42782521 is about 349.7481753184.

The spelling of 42782521 in words is "forty-two million, seven hundred eighty-two thousand, five hundred twenty-one".