42428381 has 4 divisors (see below), whose sum is σ = 43575132. Its totient is φ = 41281632.

The previous prime is 42428369. The next prime is 42428417. The reversal of 42428381 is 18382424.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30415225 + 12013156 = 5515^2 + 3466^2 .

It is a cyclic number.

It is not a de Polignac number, because 42428381 - 2¹⁴ = 42411997 is a prime.

It is a super-2 number, since 2×42428381² = 3600335028562322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42428341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 573320 + ... + 573393.

It is an arithmetic number, because the mean of its divisors is an integer number (10893783).

Almost surely, 2^42428381 is an apocalyptic number.

It is an amenable number.

42428381 is a deficient number, since it is larger than the sum of its proper divisors (1146751).

42428381 is a wasteful number, since it uses less digits than its factorization.

42428381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1146750.

The product of its digits is 12288, while the sum is 32.

The square root of 42428381 is about 6513.7071625918. The cubic root of 42428381 is about 348.7804658149.

The spelling of 42428381 in words is "forty-two million, four hundred twenty-eight thousand, three hundred eighty-one".