42491778 has 32 divisors (see below), whose sum is σ = 97511040. Its totient is φ = 12092160.

The previous prime is 42491777. The next prime is 42491819. The reversal of 42491778 is 87719424.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (42491777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9418 + ... + 13178.

It is an arithmetic number, because the mean of its divisors is an integer number (3047220).

Almost surely, 2^42491778 is an apocalyptic number.

42491778 is an abundant number, since it is smaller than the sum of its proper divisors (55019262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42491778 is a wasteful number, since it uses less digits than its factorization.

42491778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4042.

The product of its digits is 112896, while the sum is 42.

The square root of 42491778 is about 6518.5717760872. The cubic root of 42491778 is about 348.9540966931.

The spelling of 42491778 in words is "forty-two million, four hundred ninety-one thousand, seven hundred seventy-eight".