42655021 has 2 divisors, whose sum is σ = 42655022. Its totient is φ = 42655020.

The previous prime is 42655013. The next prime is 42655033. The reversal of 42655021 is 12055624.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27678121 + 14976900 = 5261^2 + 3870^2 .

It is a cyclic number.

It is not a de Polignac number, because 42655021 - 2³ = 42655013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42655121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21327510 + 21327511.

It is an arithmetic number, because the mean of its divisors is an integer number (21327511).

Almost surely, 2^42655021 is an apocalyptic number.

It is an amenable number.

42655021 is a deficient number, since it is larger than the sum of its proper divisors (1).

42655021 is an equidigital number, since it uses as much as digits as its factorization.

42655021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 42655021 is about 6531.0811509275. The cubic root of 42655021 is about 349.4003910425.

The spelling of 42655021 in words is "forty-two million, six hundred fifty-five thousand, twenty-one".