12861500817541 has 4 divisors (see below), whose sum is σ = 12861648532684. Its totient is φ = 12861353102400.

The previous prime is 12861500817499. The next prime is 12861500817551. The reversal of 12861500817541 is 14571800516821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6291839789316 + 6569661028225 = 2508354^2 + 2563135^2 .

It is a cyclic number.

It is not a de Polignac number, because 12861500817541 - 2⁷ = 12861500817413 is a prime.

It is a super-2 number, since 2×12861500817541² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12861500817551) 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, 73726890 + ... + 73901131.

It is an arithmetic number, because the mean of its divisors is an integer number (3215412133171).

Almost surely, 2^{12861500817541} is an apocalyptic number.

It is an amenable number.

12861500817541 is a deficient number, since it is larger than the sum of its proper divisors (147715143).

12861500817541 is an equidigital number, since it uses as much as digits as its factorization.

12861500817541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147715142.

The product of its (nonzero) digits is 537600, while the sum is 49.

The spelling of 12861500817541 in words is "twelve trillion, eight hundred sixty-one billion, five hundred million, eight hundred seventeen thousand, five hundred forty-one".