42505381 has 2 divisors, whose sum is σ = 42505382. Its totient is φ = 42505380.

The previous prime is 42505369. The next prime is 42505427. The reversal of 42505381 is 18350524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42185025 + 320356 = 6495^2 + 566^2 .

It is a cyclic number.

It is not a de Polignac number, because 42505381 - 2¹⁷ = 42374309 is a prime.

It is a super-2 number, since 2×42505381² = 3613414827910322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42505181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21252690 + 21252691.

It is an arithmetic number, because the mean of its divisors is an integer number (21252691).

Almost surely, 2^42505381 is an apocalyptic number.

It is an amenable number.

42505381 is a deficient number, since it is larger than the sum of its proper divisors (1).

42505381 is an equidigital number, since it uses as much as digits as its factorization.

42505381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 42505381 is about 6519.6150960007. The cubic root of 42505381 is about 348.9913299051.

The spelling of 42505381 in words is "forty-two million, five hundred five thousand, three hundred eighty-one".