1321905312 has 768 divisors, whose sum is σ = 5364817920. Its totient is φ = 306561024.

The previous prime is 1321905311. The next prime is 1321905323. The reversal of 1321905312 is 2135091231.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321905311) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 30741963 + ... + 30742005.

It is an arithmetic number, because the mean of its divisors is an integer number (6985440).

Almost surely, 2^1321905312 is an apocalyptic number.

1321905312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1321905312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2682408960).

1321905312 is an abundant number, since it is smaller than the sum of its proper divisors (4042912608).

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

1321905312 is a wasteful number, since it uses less digits than its factorization.

1321905312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 1321905312 is about 36358.0157874436. The cubic root of 1321905312 is about 1097.4888480489.

Adding to 1321905312 its reverse (2135091231), we get a palindrome (3456996543).

The spelling of 1321905312 in words is "one billion, three hundred twenty-one million, nine hundred five thousand, three hundred twelve".