1321321650 has 48 divisors (see below), whose sum is σ = 3574780128. Its totient is φ = 320320000.

The previous prime is 1321321643. The next prime is 1321321657. The reversal of 1321321650 is 561231231.

It is an interprime number because it is at equal distance from previous prime (1321321643) and next prime (1321321657).

It is a self number, because there is not a number n which added to its sum of digits gives 1321321650.

It is not an unprimeable number, because it can be changed into a prime (1321321657) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 398751 + ... + 402050.

It is an arithmetic number, because the mean of its divisors is an integer number (74474586).

Almost surely, 2^1321321650 is an apocalyptic number.

1321321650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1321321650 is an abundant number, since it is smaller than the sum of its proper divisors (2253458478).

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

1321321650 is a wasteful number, since it uses less digits than its factorization.

1321321650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800827 (or 800822 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 1321321650 is about 36349.9883081137. The cubic root of 1321321650 is about 1097.3272992023.

Adding to 1321321650 its reverse (561231231), we get a palindrome (1882552881).

The spelling of 1321321650 in words is "one billion, three hundred twenty-one million, three hundred twenty-one thousand, six hundred fifty".