1311521540 has 24 divisors (see below), whose sum is σ = 3147652032. Its totient is φ = 449664480.

The previous prime is 1311521539. The next prime is 1311521567. The reversal of 1311521540 is 451251131.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4683866 + ... + 4684145.

It is an arithmetic number, because the mean of its divisors is an integer number (131152168).

Almost surely, 2^1311521540 is an apocalyptic number.

1311521540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311521540 is an abundant number, since it is smaller than the sum of its proper divisors (1836130492).

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

1311521540 is a wasteful number, since it uses less digits than its factorization.

1311521540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9368027 (or 9368025 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 1311521540 is about 36214.9353167999. The cubic root of 1311521540 is about 1094.6076421404.

Adding to 1311521540 its reverse (451251131), we get a palindrome (1762772671).

The spelling of 1311521540 in words is "one billion, three hundred eleven million, five hundred twenty-one thousand, five hundred forty".