442781640 has 240 divisors, whose sum is σ = 1731836700. Its totient is φ = 101170944.

The previous prime is 442781639. The next prime is 442781641. The reversal of 442781640 is 46187244.

442781640 is a `hidden beast` number, since 4 + 4 + 2 + 7 + 8 + 1 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (442781639) and next prime (442781641).

It can be written as a sum of positive squares in 2 ways, for example, as 442765764 + 15876 = 21042^2 + 126^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 442781595 and 442781604.

It is not an unprimeable number, because it can be changed into a prime (442781641) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 157366 + ... + 160154.

Almost surely, 2^442781640 is an apocalyptic number.

442781640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 442781640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (865918350).

442781640 is an abundant number, since it is smaller than the sum of its proper divisors (1289055060).

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

442781640 is a wasteful number, since it uses less digits than its factorization.

442781640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2826 (or 2806 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The square root of 442781640 is about 21042.3772421274. The cubic root of 442781640 is about 762.1899210400.

The spelling of 442781640 in words is "four hundred forty-two million, seven hundred eighty-one thousand, six hundred forty".