42379781 has 2 divisors, whose sum is σ = 42379782. Its totient is φ = 42379780.

The previous prime is 42379769. The next prime is 42379847. The reversal of 42379781 is 18797324.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24453025 + 17926756 = 4945^2 + 4234^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42379781 is a prime.

It is a super-2 number, since 2×42379781² = 3592091675215922, 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 (42379751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21189890 + 21189891.

It is an arithmetic number, because the mean of its divisors is an integer number (21189891).

Almost surely, 2^42379781 is an apocalyptic number.

It is an amenable number.

42379781 is a deficient number, since it is larger than the sum of its proper divisors (1).

42379781 is an equidigital number, since it uses as much as digits as its factorization.

42379781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 41.

The square root of 42379781 is about 6509.9754991858. The cubic root of 42379781 is about 348.6472436140.

The spelling of 42379781 in words is "forty-two million, three hundred seventy-nine thousand, seven hundred eighty-one".