42126521 has 2 divisors, whose sum is σ = 42126522. Its totient is φ = 42126520.

The previous prime is 42126517. The next prime is 42126533. The reversal of 42126521 is 12562124.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26214400 + 15912121 = 5120^2 + 3989^2 .

It is a cyclic number.

It is not a de Polignac number, because 42126521 - 2² = 42126517 is a prime.

It is not a weakly prime, because it can be changed into another prime (42125521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21063260 + 21063261.

It is an arithmetic number, because the mean of its divisors is an integer number (21063261).

Almost surely, 2^42126521 is an apocalyptic number.

It is an amenable number.

42126521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42126521 is an equidigital number, since it uses as much as digits as its factorization.

42126521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 23.

The square root of 42126521 is about 6490.4946652778. The cubic root of 42126521 is about 347.9513545647.

Adding to 42126521 its reverse (12562124), we get a palindrome (54688645).

The spelling of 42126521 in words is "forty-two million, one hundred twenty-six thousand, five hundred twenty-one".