42505640 has 32 divisors (see below), whose sum is σ = 96525000. Its totient is φ = 16844544.

The previous prime is 42505621. The next prime is 42505649. The reversal of 42505640 is 4650524.

It can be written as a sum of positive squares in 4 ways, for example, as 30492484 + 12013156 = 5522^2 + 3466^2 .

It is not an unprimeable number, because it can be changed into a prime (42505649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515 + ... + 9234.

Almost surely, 2^42505640 is an apocalyptic number.

42505640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

42505640 is an abundant number, since it is smaller than the sum of its proper divisors (54019360).

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

42505640 is a wasteful number, since it uses less digits than its factorization.

42505640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9869 (or 9865 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 42505640 is about 6519.6349591062. The cubic root of 42505640 is about 348.9920387453.

The spelling of 42505640 in words is "forty-two million, five hundred five thousand, six hundred forty".