2051321311240 has 128 divisors (see below), whose sum is σ = 4753487138400. Its totient is φ = 796120842240.

The previous prime is 2051321311187. The next prime is 2051321311283. The reversal of 2051321311240 is 421131231502.

It can be written as a sum of positive squares in 16 ways, for example, as 274682906404 + 1776638404836 = 524102^2 + 1332906^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1385091300 + ... + 1385092780.

Almost surely, 2^{2051321311240} is an apocalyptic number.

2051321311240 is a gapful number since it is divisible by the number (20) 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 2051321311240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2376743569200).

2051321311240 is an abundant number, since it is smaller than the sum of its proper divisors (2702165827160).

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

2051321311240 is a wasteful number, since it uses less digits than its factorization.

2051321311240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3515 (or 3511 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 2051321311240 its reverse (421131231502), we get a palindrome (2472452542742).

The spelling of 2051321311240 in words is "two trillion, fifty-one billion, three hundred twenty-one million, three hundred eleven thousand, two hundred forty".