42321581 has 2 divisors, whose sum is σ = 42321582. Its totient is φ = 42321580.

The previous prime is 42321571. The next prime is 42321611. The reversal of 42321581 is 18512324.

42321581 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., 25593481 + 16728100 = 5059^2 + 4090^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42321581 is a prime.

It is a super-2 number, since 2×42321581² = 3582232436679122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42321581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42321511) 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, 21160790 + 21160791.

It is an arithmetic number, because the mean of its divisors is an integer number (21160791).

Almost surely, 2^42321581 is an apocalyptic number.

It is an amenable number.

42321581 is a deficient number, since it is larger than the sum of its proper divisors (1).

42321581 is an equidigital number, since it uses as much as digits as its factorization.

42321581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1920, while the sum is 26.

The square root of 42321581 is about 6505.5039005445. The cubic root of 42321581 is about 348.4875718331.

The spelling of 42321581 in words is "forty-two million, three hundred twenty-one thousand, five hundred eighty-one".