1321005642 has 48 divisors (see below), whose sum is σ = 2911065696. Its totient is φ = 399335200.

The previous prime is 1321005619. The next prime is 1321005659. The reversal of 1321005642 is 2465001231.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 332713 + ... + 336659.

It is an arithmetic number, because the mean of its divisors is an integer number (60647202).

Almost surely, 2^1321005642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1321005642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1455532848).

1321005642 is an abundant number, since it is smaller than the sum of its proper divisors (1590060054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1321005642 is a wasteful number, since it uses less digits than its factorization.

1321005642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4435 (or 4424 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 1321005642 is about 36345.6413067647. The cubic root of 1321005642 is about 1097.2398130976.

Adding to 1321005642 its reverse (2465001231), we get a palindrome (3786006873).

The spelling of 1321005642 in words is "one billion, three hundred twenty-one million, five thousand, six hundred forty-two".