42191378 has 8 divisors (see below), whose sum is σ = 64830780. Its totient is φ = 20581120.

The previous prime is 42191371. The next prime is 42191447. The reversal of 42191378 is 87319124.

It can be written as a sum of positive squares in 2 ways, for example, as 35724529 + 6466849 = 5977^2 + 2543^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×42191378² = 3560224755077768, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42191371) 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, 257183 + ... + 257346.

Almost surely, 2^42191378 is an apocalyptic number.

42191378 is a deficient number, since it is larger than the sum of its proper divisors (22639402).

42191378 is a wasteful number, since it uses less digits than its factorization.

42191378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514572.

The product of its digits is 12096, while the sum is 35.

The square root of 42191378 is about 6495.4890501024. The cubic root of 42191378 is about 348.1298289091.

The spelling of 42191378 in words is "forty-two million, one hundred ninety-one thousand, three hundred seventy-eight".