1321526440 has 64 divisors (see below), whose sum is σ = 3227535360. Its totient is φ = 484081920.

The previous prime is 1321526417. The next prime is 1321526449. The reversal of 1321526440 is 446251231.

It is a junction number, because it is equal to n+sod(n) for n = 1321526399 and 1321526408.

It is not an unprimeable number, because it can be changed into a prime (1321526449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56035 + ... + 76045.

It is an arithmetic number, because the mean of its divisors is an integer number (50430240).

Almost surely, 2^1321526440 is an apocalyptic number.

1321526440 is a gapful number since it is divisible by the number (10) 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 1321526440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1613767680).

1321526440 is an abundant number, since it is smaller than the sum of its proper divisors (1906008920).

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

1321526440 is a wasteful number, since it uses less digits than its factorization.

1321526440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20162 (or 20158 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 1321526440 is about 36352.8051187250. The cubic root of 1321526440 is about 1097.3839874051.

Adding to 1321526440 its reverse (446251231), we get a palindrome (1767777671).

The spelling of 1321526440 in words is "one billion, three hundred twenty-one million, five hundred twenty-six thousand, four hundred forty".