1321613661 has 8 divisors (see below), whose sum is σ = 1768852800. Its totient is φ = 877725152.

The previous prime is 1321613653. The next prime is 1321613663. The reversal of 1321613661 is 1663161231.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1321613661 - 2³ = 1321613653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321613663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 836736 + ... + 838313.

It is an arithmetic number, because the mean of its divisors is an integer number (221106600).

Almost surely, 2^1321613661 is an apocalyptic number.

It is an amenable number.

1321613661 is a deficient number, since it is larger than the sum of its proper divisors (447239139).

1321613661 is a wasteful number, since it uses less digits than its factorization.

1321613661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1675315.

The product of its digits is 3888, while the sum is 30.

The square root of 1321613661 is about 36354.0047450071. The cubic root of 1321613661 is about 1097.4081293923.

Adding to 1321613661 its reverse (1663161231), we get a palindrome (2984774892).

The spelling of 1321613661 in words is "one billion, three hundred twenty-one million, six hundred thirteen thousand, six hundred sixty-one".