2131261440 has 768 divisors, whose sum is σ = 9170703360. Its totient is φ = 408944640.

The previous prime is 2131261427. The next prime is 2131261463. The reversal of 2131261440 is 441621312.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 2131261440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 40212454 + ... + 40212506.

It is an arithmetic number, because the mean of its divisors is an integer number (11941020).

Almost surely, 2^2131261440 is an apocalyptic number.

2131261440 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 2131261440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4585351680).

2131261440 is an abundant number, since it is smaller than the sum of its proper divisors (7039441920).

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

2131261440 is a wasteful number, since it uses less digits than its factorization.

2131261440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 2131261440 is about 46165.5871835288. The cubic root of 2131261440 is about 1286.9022963570.

Adding to 2131261440 its reverse (441621312), we get a palindrome (2572882752).

The spelling of 2131261440 in words is "two billion, one hundred thirty-one million, two hundred sixty-one thousand, four hundred forty".