12561465535501 has 4 divisors (see below), whose sum is σ = 12562445305404. Its totient is φ = 12560485765600.

The previous prime is 12561465535481. The next prime is 12561465535543. The reversal of 12561465535501 is 10553556416521.

12561465535501 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 7659443704900 + 4902021830601 = 2767570^2 + 2214051^2 .

It is a cyclic number.

It is not a de Polignac number, because 12561465535501 - 2⁴¹ = 10362442279949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561465535561) 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, 489865720 + ... + 489891361.

It is an arithmetic number, because the mean of its divisors is an integer number (3140611326351).

Almost surely, 2^{12561465535501} is an apocalyptic number.

It is an amenable number.

12561465535501 is a deficient number, since it is larger than the sum of its proper divisors (979769903).

12561465535501 is an equidigital number, since it uses as much as digits as its factorization.

12561465535501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979769902.

The product of its (nonzero) digits is 2700000, while the sum is 49.

The spelling of 12561465535501 in words is "twelve trillion, five hundred sixty-one billion, four hundred sixty-five million, five hundred thirty-five thousand, five hundred one".