42781865 has 16 divisors (see below), whose sum is σ = 59781888. Its totient is φ = 28781376.

The previous prime is 42781859. The next prime is 42781889. The reversal of 42781865 is 56818724.

It is a cyclic number.

It is not a de Polignac number, because 42781865 - 2¹⁸ = 42519721 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9677 + ... + 13386.

It is an arithmetic number, because the mean of its divisors is an integer number (3736368).

Almost surely, 2^42781865 is an apocalyptic number.

It is an amenable number.

42781865 is a deficient number, since it is larger than the sum of its proper divisors (17000023).

42781865 is a wasteful number, since it uses less digits than its factorization.

42781865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23128.

The product of its digits is 107520, while the sum is 41.

The square root of 42781865 is about 6540.7847388521. The cubic root of 42781865 is about 349.7463877038.

The spelling of 42781865 in words is "forty-two million, seven hundred eighty-one thousand, eight hundred sixty-five".