1006587721 has 8 divisors (see below), whose sum is σ = 1017908360. Its totient is φ = 995286528.

The previous prime is 1006587683. The next prime is 1006587737. The reversal of 1006587721 is 1277856001.

It can be written as a sum of positive squares in 4 ways, for example, as 424813321 + 581774400 = 20611^2 + 24120^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1006587721 - 2⁹ = 1006587209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1006587781) 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, 115795 + ... + 124183.

It is an arithmetic number, because the mean of its divisors is an integer number (127238545).

Almost surely, 2^1006587721 is an apocalyptic number.

It is an amenable number.

1006587721 is a deficient number, since it is larger than the sum of its proper divisors (11320639).

1006587721 is an equidigital number, since it uses as much as digits as its factorization.

1006587721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9723.

The product of its (nonzero) digits is 23520, while the sum is 37.

The square root of 1006587721 is about 31726.7666332389. The cubic root of 1006587721 is about 1002.1911025631.

The spelling of 1006587721 in words is "one billion, six million, five hundred eighty-seven thousand, seven hundred twenty-one".