42644778 has 64 divisors (see below), whose sum is σ = 101191680. Its totient is φ = 11836800.

The previous prime is 42644741. The next prime is 42644779. The reversal of 42644778 is 87744624.

It is not an unprimeable number, because it can be changed into a prime (42644779) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38326 + ... + 39422.

It is an arithmetic number, because the mean of its divisors is an integer number (1581120).

Almost surely, 2^42644778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42644778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50595840).

42644778 is an abundant number, since it is smaller than the sum of its proper divisors (58546902).

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

42644778 is a wasteful number, since it uses less digits than its factorization.

42644778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163.

The product of its digits is 301056, while the sum is 42.

The square root of 42644778 is about 6530.2969304619. The cubic root of 42644778 is about 349.3724209495.

The spelling of 42644778 in words is "forty-two million, six hundred forty-four thousand, seven hundred seventy-eight".