1311857521 has 16 divisors (see below), whose sum is σ = 1457420608. Its totient is φ = 1173268800.

The previous prime is 1311857501. The next prime is 1311857531. The reversal of 1311857521 is 1257581131.

It is a cyclic number.

It is not a de Polignac number, because 1311857521 - 2¹⁵ = 1311824753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311857501) 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, 40786 + ... + 65476.

It is an arithmetic number, because the mean of its divisors is an integer number (91088788).

Almost surely, 2^1311857521 is an apocalyptic number.

It is an amenable number.

1311857521 is a deficient number, since it is larger than the sum of its proper divisors (145563087).

1311857521 is a wasteful number, since it uses less digits than its factorization.

1311857521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24832.

The product of its digits is 8400, while the sum is 34.

The square root of 1311857521 is about 36219.5737274750. The cubic root of 1311857521 is about 1094.7011050787.

The spelling of 1311857521 in words is "one billion, three hundred eleven million, eight hundred fifty-seven thousand, five hundred twenty-one".