42125521 has 2 divisors, whose sum is σ = 42125522. Its totient is φ = 42125520.

The previous prime is 42125477. The next prime is 42125537. The reversal of 42125521 is 12552124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41783296 + 342225 = 6464^2 + 585^2 .

It is a cyclic number.

It is not a de Polignac number, because 42125521 - 2⁷ = 42125393 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42125492 and 42125501.

It is not a weakly prime, because it can be changed into another prime (42125561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21062760 + 21062761.

It is an arithmetic number, because the mean of its divisors is an integer number (21062761).

Almost surely, 2^42125521 is an apocalyptic number.

It is an amenable number.

42125521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42125521 is an equidigital number, since it uses as much as digits as its factorization.

42125521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 800, while the sum is 22.

The square root of 42125521 is about 6490.4176290898. The cubic root of 42125521 is about 347.9486013181.

Adding to 42125521 its reverse (12552124), we get a palindrome (54677645).

The spelling of 42125521 in words is "forty-two million, one hundred twenty-five thousand, five hundred twenty-one".