1005721 has 8 divisors (see below), whose sum is σ = 1065600. Its totient is φ = 947232.

The previous prime is 1005709. The next prime is 1005751. The reversal of 1005721 is 1275001.

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

It is not a de Polignac number, because 1005721 - 2⁷ = 1005593 is a prime.

It is a super-2 number, since 2×1005721² = 2022949459682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1005695 and 1005704.

It is not an unprimeable number, because it can be changed into a prime (1005701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1380 + ... + 1978.

It is an arithmetic number, because the mean of its divisors is an integer number (133200).

2^1005721 is an apocalyptic number.

It is an amenable number.

1005721 is a deficient number, since it is larger than the sum of its proper divisors (59879).

1005721 is an equidigital number, since it uses as much as digits as its factorization.

1005721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 1005721 is about 1002.8564204312. The cubic root of 1005721 is about 100.1903374866.

The spelling of 1005721 in words is "one million, five thousand, seven hundred twenty-one".