2643196375681 has 3 divisors (see below), whose sum is σ = 2643198001473. Its totient is φ = 2643194749890.

The previous prime is 2643196375679. The next prime is 2643196375693. The reversal of 2643196375681 is 1865736913462.

It is a happy number.

The square root of 2643196375681 is 1625791.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 2643196375681 - 2¹ = 2643196375679 is a prime.

It is a super-2 number, since 2×2643196375681² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2643196385681) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 812896 + ... + 2438686.

It is an arithmetic number, because the mean of its divisors is an integer number (881066000491).

Almost surely, 2^{2643196375681} is an apocalyptic number.

2643196375681 is the 1625791-st square number.

2643196375681 is the 812896-th centered octagonal number.

It is an amenable number.

2643196375681 is a deficient number, since it is larger than the sum of its proper divisors (1625792).

2643196375681 is an frugal number, since it uses more digits than its factorization.

2643196375681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3251582 (or 1625791 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 61.

The spelling of 2643196375681 in words is "two trillion, six hundred forty-three billion, one hundred ninety-six million, three hundred seventy-five thousand, six hundred eighty-one".