42008781 has 8 divisors (see below), whose sum is σ = 56173600. Its totient is φ = 27924912.

The previous prime is 42008777. The next prime is 42008789. The reversal of 42008781 is 18780024.

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

It is not a de Polignac number, because 42008781 - 2² = 42008777 is a prime.

It is a super-2 number, since 2×42008781² = 3529475362211922, 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 (42008789) 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, 19015 + ... + 21108.

It is an arithmetic number, because the mean of its divisors is an integer number (7021700).

Almost surely, 2^42008781 is an apocalyptic number.

It is an amenable number.

42008781 is a deficient number, since it is larger than the sum of its proper divisors (14164819).

42008781 is a wasteful number, since it uses less digits than its factorization.

42008781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40475.

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 42008781 is about 6481.4181318597. The cubic root of 42008781 is about 347.6268873958.

The spelling of 42008781 in words is "forty-two million, eight thousand, seven hundred eighty-one".