1002661 has 4 divisors (see below), whose sum is σ = 1093824. Its totient is φ = 911500.

The previous prime is 1002653. The next prime is 1002679. The reversal of 1002661 is 1662001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1662001 = 11 ⋅151091.

It is a cyclic number.

It is not a de Polignac number, because 1002661 - 2³ = 1002653 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002061) 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 3 ways as a sum of consecutive naturals, for example, 45565 + ... + 45586.

It is an arithmetic number, because the mean of its divisors is an integer number (273456).

2^1002661 is an apocalyptic number.

1002661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1002661 is a deficient number, since it is larger than the sum of its proper divisors (91163).

1002661 is an equidigital number, since it uses as much as digits as its factorization.

1002661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91162.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1002661 is about 1001.3296160606. The cubic root of 1002661 is about 100.0886214392.

Adding to 1002661 its reverse (1662001), we get a palindrome (2664662).

The spelling of 1002661 in words is "one million, two thousand, six hundred sixty-one".