42566621 has 2 divisors, whose sum is σ = 42566622. Its totient is φ = 42566620.

The previous prime is 42566611. The next prime is 42566659. The reversal of 42566621 is 12666524.

42566621 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., 36120100 + 6446521 = 6010^2 + 2539^2 .

It is a cyclic number.

It is not a de Polignac number, because 42566621 - 2¹⁸ = 42304477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42566611) 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, 21283310 + 21283311.

It is an arithmetic number, because the mean of its divisors is an integer number (21283311).

Almost surely, 2^42566621 is an apocalyptic number.

It is an amenable number.

42566621 is a deficient number, since it is larger than the sum of its proper divisors (1).

42566621 is an equidigital number, since it uses as much as digits as its factorization.

42566621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

The square root of 42566621 is about 6524.3100018316. The cubic root of 42566621 is about 349.1588535822.

The spelling of 42566621 in words is "forty-two million, five hundred sixty-six thousand, six hundred twenty-one".