1321641 has 6 divisors (see below), whose sum is σ = 1909050. Its totient is φ = 881088.

The previous prime is 1321637. The next prime is 1321651. The reversal of 1321641 is 1461231.

It is a happy number.

1321641 is a `hidden beast` number, since 1 + 3 + 21 + 641 = 666.

It can be written as a sum of positive squares in only one way, i.e., 837225 + 484416 = 915^2 + 696^2 .

It is not a de Polignac number, because 1321641 - 2² = 1321637 is a prime.

It is a super-3 number, since 3×1321641³ = 6925669510283333163, which contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1321601) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73416 + ... + 73433.

It is an arithmetic number, because the mean of its divisors is an integer number (318175).

2^1321641 is an apocalyptic number.

It is an amenable number.

1321641 is a deficient number, since it is larger than the sum of its proper divisors (587409).

1321641 is a wasteful number, since it uses less digits than its factorization.

1321641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146855 (or 146852 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1321641 is about 1149.6264610733. The cubic root of 1321641 is about 109.7415696363.

Adding to 1321641 its reverse (1461231), we get a palindrome (2782872).

It can be divided in two parts, 132 and 1641, that multiplied together give a palindrome (216612).

The spelling of 1321641 in words is "one million, three hundred twenty-one thousand, six hundred forty-one".