42191819 has 4 divisors (see below), whose sum is σ = 42222696. Its totient is φ = 42160944.

The previous prime is 42191791. The next prime is 42191861. The reversal of 42191819 is 91819124.

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

It is a cyclic number.

It is not a de Polignac number, because 42191819 - 2²⁰ = 41143243 is a prime.

It is a super-2 number, since 2×42191819² = 3560299181057522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42191119) 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, 13289 + ... + 16154.

It is an arithmetic number, because the mean of its divisors is an integer number (10555674).

Almost surely, 2^42191819 is an apocalyptic number.

42191819 is a deficient number, since it is larger than the sum of its proper divisors (30877).

42191819 is a wasteful number, since it uses less digits than its factorization.

42191819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30876.

The product of its digits is 5184, while the sum is 35.

The square root of 42191819 is about 6495.5229966493. The cubic root of 42191819 is about 348.1310418324.

The spelling of 42191819 in words is "forty-two million, one hundred ninety-one thousand, eight hundred nineteen".