1020661 has 4 divisors (see below), whose sum is σ = 1074400. Its totient is φ = 966924.

The previous prime is 1020631. The next prime is 1020667. The reversal of 1020661 is 1660201.

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.

It is a cyclic number.

It is not a de Polignac number, because 1020661 - 2¹¹ = 1018613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26841 + ... + 26878.

It is an arithmetic number, because the mean of its divisors is an integer number (268600).

2^1020661 is an apocalyptic number.

It is an amenable number.

1020661 is a deficient number, since it is larger than the sum of its proper divisors (53739).

1020661 is an equidigital number, since it uses as much as digits as its factorization.

1020661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53738.

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

The square root of 1020661 is about 1010.2776845996. The cubic root of 1020661 is about 100.6840106270.

Adding to 1020661 its reverse (1660201), we get a palindrome (2680862).

It can be divided in two parts, 1020 and 661, that added together give a square (1681 = 41²).

The spelling of 1020661 in words is "one million, twenty thousand, six hundred sixty-one".