1321366523543 has 4 divisors (see below), whose sum is σ = 1441490752968. Its totient is φ = 1201242294120.

The previous prime is 1321366523531. The next prime is 1321366523579. The reversal of 1321366523543 is 3453256631231.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1321366523543 - 2¹⁸ = 1321366261399 is a prime.

It is a super-2 number, since 2×1321366523543² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321366523494 and 1321366523503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321366520543) 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, 60062114696 + ... + 60062114717.

It is an arithmetic number, because the mean of its divisors is an integer number (360372688242).

Almost surely, 2^{1321366523543} is an apocalyptic number.

1321366523543 is a deficient number, since it is larger than the sum of its proper divisors (120124229425).

1321366523543 is a wasteful number, since it uses less digits than its factorization.

1321366523543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120124229424.

The product of its digits is 1166400, while the sum is 44.

The spelling of 1321366523543 in words is "one trillion, three hundred twenty-one billion, three hundred sixty-six million, five hundred twenty-three thousand, five hundred forty-three".