1261133661513 has 16 divisors (see below), whose sum is σ = 1834433231616. Its totient is φ = 764299682640.

The previous prime is 1261133661499. The next prime is 1261133661547. The reversal of 1261133661513 is 3151663311621.

It is not a de Polignac number, because 1261133661513 - 2¹² = 1261133657417 is a prime.

It is a super-2 number, since 2×1261133661513² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1261133661583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 515370 + ... + 1669692.

It is an arithmetic number, because the mean of its divisors is an integer number (114652076976).

Almost surely, 2^{1261133661513} is an apocalyptic number.

It is an amenable number.

1261133661513 is a deficient number, since it is larger than the sum of its proper divisors (573299570103).

1261133661513 is a wasteful number, since it uses less digits than its factorization.

1261133661513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1187444.

The product of its digits is 58320, while the sum is 39.

The spelling of 1261133661513 in words is "one trillion, two hundred sixty-one billion, one hundred thirty-three million, six hundred sixty-one thousand, five hundred thirteen".