1001553 has 16 divisors (see below), whose sum is σ = 1568640. Its totient is φ = 556416.

The previous prime is 1001551. The next prime is 1001563. The reversal of 1001553 is 3551001.

It is not a de Polignac number, because 1001553 - 2¹ = 1001551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1001551) 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, 133 + ... + 1421.

It is an arithmetic number, because the mean of its divisors is an integer number (98040).

2^1001553 is an apocalyptic number.

It is an amenable number.

1001553 is a deficient number, since it is larger than the sum of its proper divisors (567087).

1001553 is a wasteful number, since it uses less digits than its factorization.

1001553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336.

The product of its (nonzero) digits is 75, while the sum is 15.

The square root of 1001553 is about 1000.7761987577. The cubic root of 1001553 is about 100.0517398919.

Adding to 1001553 its reverse (3551001), we get a palindrome (4552554).

It can be divided in two parts, 100 and 1553, that added together give a triangular number (1653 = T₅₇).

The spelling of 1001553 in words is "one million, one thousand, five hundred fifty-three".