1001072721 has 16 divisors (see below), whose sum is σ = 1506317760. Its totient is φ = 585789120.

The previous prime is 1001072719. The next prime is 1001072729. The reversal of 1001072721 is 1272701001.

It is a happy number.

1001072721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1001072721 - 2¹ = 1001072719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1001072729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 522070 + ... + 523983.

It is an arithmetic number, because the mean of its divisors is an integer number (94144860).

Almost surely, 2^1001072721 is an apocalyptic number.

1001072721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1001072721 is a deficient number, since it is larger than the sum of its proper divisors (505245039).

1001072721 is a wasteful number, since it uses less digits than its factorization.

1001072721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046096.

The product of its (nonzero) digits is 196, while the sum is 21.

The square root of 1001072721 is about 31639.7332637303. The cubic root of 1001072721 is about 1000.3574458839.

Adding to 1001072721 its reverse (1272701001), we get a palindrome (2273773722).

The spelling of 1001072721 in words is "one billion, one million, seventy-two thousand, seven hundred twenty-one".