1311745626521 has 4 divisors (see below), whose sum is σ = 1430995228944. Its totient is φ = 1192496024100.

The previous prime is 1311745626509. The next prime is 1311745626559. The reversal of 1311745626521 is 1256265471131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311745626521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311745626571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59624801195 + ... + 59624801216.

It is an arithmetic number, because the mean of its divisors is an integer number (357748807236).

Almost surely, 2^{1311745626521} is an apocalyptic number.

1311745626521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1311745626521 is a deficient number, since it is larger than the sum of its proper divisors (119249602423).

1311745626521 is a wasteful number, since it uses less digits than its factorization.

1311745626521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119249602422.

The product of its digits is 302400, while the sum is 44.

The spelling of 1311745626521 in words is "one trillion, three hundred eleven billion, seven hundred forty-five million, six hundred twenty-six thousand, five hundred twenty-one".