42781819 has 8 divisors (see below), whose sum is σ = 43995168. Its totient is φ = 41576640.

The previous prime is 42781811. The next prime is 42781841. The reversal of 42781819 is 91818724.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 42781819 - 2³ = 42781811 is a prime.

It is a super-2 number, since 2×42781819² = 3660568073897522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42781811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9474 + ... + 13240.

It is an arithmetic number, because the mean of its divisors is an integer number (5499396).

Almost surely, 2^42781819 is an apocalyptic number.

42781819 is a deficient number, since it is larger than the sum of its proper divisors (1213349).

42781819 is a wasteful number, since it uses less digits than its factorization.

42781819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4085.

The product of its digits is 32256, while the sum is 40.

The square root of 42781819 is about 6540.7812224535. The cubic root of 42781819 is about 349.7462623521.

The spelling of 42781819 in words is "forty-two million, seven hundred eighty-one thousand, eight hundred nineteen".