42851809 has 48 divisors (see below), whose sum is σ = 60082560. Its totient is φ = 29652480.

The previous prime is 42851807. The next prime is 42851813. The reversal of 42851809 is 90815824.

It is not a de Polignac number, because 42851809 - 2¹ = 42851807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42851801) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 481437 + ... + 481525.

It is an arithmetic number, because the mean of its divisors is an integer number (1251720).

Almost surely, 2^42851809 is an apocalyptic number.

It is an amenable number.

42851809 is a deficient number, since it is larger than the sum of its proper divisors (17230751).

42851809 is a wasteful number, since it uses less digits than its factorization.

42851809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 42851809 is about 6546.1293143353. The cubic root of 42851809 is about 349.9368838569.

It can be divided in two parts, 42851 and 809, that added together give a triangular number (43660 = T₂₉₅).

The spelling of 42851809 in words is "forty-two million, eight hundred fifty-one thousand, eight hundred nine".