1365551625661 has 4 divisors (see below), whose sum is σ = 1365954565500. Its totient is φ = 1365148685824.

The previous prime is 1365551625631. The next prime is 1365551625701. The reversal of 1365551625661 is 1665261555631.

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 784154525625 + 581397100036 = 885525^2 + 762494^2 .

It is a cyclic number.

It is not a de Polignac number, because 1365551625661 - 2⁷ = 1365551625533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1365551625599 and 1365551625608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1365551625611) 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, 201464836 + ... + 201471613.

It is an arithmetic number, because the mean of its divisors is an integer number (341488641375).

Almost surely, 2^{1365551625661} is an apocalyptic number.

It is an amenable number.

1365551625661 is a deficient number, since it is larger than the sum of its proper divisors (402939839).

1365551625661 is an equidigital number, since it uses as much as digits as its factorization.

1365551625661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402939838.

The product of its digits is 4860000, while the sum is 52.

The spelling of 1365551625661 in words is "one trillion, three hundred sixty-five billion, five hundred fifty-one million, six hundred twenty-five thousand, six hundred sixty-one".