42398381 has 2 divisors, whose sum is σ = 42398382. Its totient is φ = 42398380.

The previous prime is 42398353. The next prime is 42398383. The reversal of 42398381 is 18389324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28185481 + 14212900 = 5309^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 42398381 - 2¹⁰ = 42397357 is a prime.

It is a super-2 number, since 2×42398381² = 3595245422842322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 42398383, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42398383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21199190 + 21199191.

It is an arithmetic number, because the mean of its divisors is an integer number (21199191).

Almost surely, 2^42398381 is an apocalyptic number.

It is an amenable number.

42398381 is a deficient number, since it is larger than the sum of its proper divisors (1).

42398381 is an equidigital number, since it uses as much as digits as its factorization.

42398381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 38.

The square root of 42398381 is about 6511.4039192789. The cubic root of 42398381 is about 348.6982419132.

The spelling of 42398381 in words is "forty-two million, three hundred ninety-eight thousand, three hundred eighty-one".