1331256747601 has 9 divisors (see below), whose sum is σ = 1463296160809. Its totient is φ = 1210221868900.

The previous prime is 1331256747553. The next prime is 1331256747607. The reversal of 1331256747601 is 1067476521331.

It is a happy number.

The square root of 1331256747601 is 1153801.

It is a perfect power (a square), and thus also a powerful number.

It is a de Polignac number, because none of the positive numbers 2^k-1331256747601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1331256747607) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12639366 + ... + 12744256.

Almost surely, 2^{1331256747601} is an apocalyptic number.

1331256747601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1331256747601 is the 1153801-st square number.

1331256747601 is the 576901-st centered octagonal number.

It is an amenable number.

1331256747601 is a deficient number, since it is larger than the sum of its proper divisors (132039413208).

1331256747601 is an frugal number, since it uses more digits than its factorization.

1331256747601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209804 (or 104902 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 46.

The spelling of 1331256747601 in words is "one trillion, three hundred thirty-one billion, two hundred fifty-six million, seven hundred forty-seven thousand, six hundred one".