42587721 has 32 divisors (see below), whose sum is σ = 72460800. Its totient is φ = 24449040.

The previous prime is 42587711. The next prime is 42587723. The reversal of 42587721 is 12778524.

42587721 is a `hidden beast` number, since 4 + 2 + 587 + 72 + 1 = 666.

It is not a de Polignac number, because 42587721 - 2¹³ = 42579529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42587723) 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, 1870 + ... + 9416.

It is an arithmetic number, because the mean of its divisors is an integer number (2264400).

Almost surely, 2^42587721 is an apocalyptic number.

It is an amenable number.

42587721 is a deficient number, since it is larger than the sum of its proper divisors (29873079).

42587721 is a wasteful number, since it uses less digits than its factorization.

42587721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7586 (or 7580 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 42587721 is about 6525.9268307268. The cubic root of 42587721 is about 349.2165359843.

The spelling of 42587721 in words is "forty-two million, five hundred eighty-seven thousand, seven hundred twenty-one".