42640000 has 160 divisors (see below), whose sum is σ = 117103140. Its totient is φ = 15360000.

The previous prime is 42639991. The next prime is 42640001. The reversal of 42640000 is 4624.

It can be written as a sum of positive squares in 10 ways, for example, as 20286016 + 22353984 = 4504^2 + 4728^2 .

It is a tau number, because it is divible by the number of its divisors (160).

It is a hoax number, since the sum of its digits (16) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (42640001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1039980 + ... + 1040020.

Almost surely, 2^42640000 is an apocalyptic number.

42640000 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 42640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58551570).

42640000 is an abundant number, since it is smaller than the sum of its proper divisors (74463140).

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

42640000 is an equidigital number, since it uses as much as digits as its factorization.

42640000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 42640000 is about 6529.9310869258. The cubic root of 42640000 is about 349.3593723509.

Adding to 42640000 its reverse (4624), we get a palindrome (42644624).

The spelling of 42640000 in words is "forty-two million, six hundred forty thousand".