42520639 has 8 divisors (see below), whose sum is σ = 48770208. Its totient is φ = 36314880.

The previous prime is 42520627. The next prime is 42520661. The reversal of 42520639 is 93602524.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 42520639 - 2⁵ = 42520607 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42520639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42520609) 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, 8842 + ... + 12775.

It is an arithmetic number, because the mean of its divisors is an integer number (6096276).

Almost surely, 2^42520639 is an apocalyptic number.

42520639 is a deficient number, since it is larger than the sum of its proper divisors (6249569).

42520639 is a wasteful number, since it uses less digits than its factorization.

42520639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21905.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 42520639 is about 6520.7851521117. The cubic root of 42520639 is about 349.0330836200.

The spelling of 42520639 in words is "forty-two million, five hundred twenty thousand, six hundred thirty-nine".