261553251266677 has 16 divisors (see below), whose sum is σ = 276124842861120. Its totient is φ = 247062547699200.

The previous prime is 261553251266621. The next prime is 261553251266687. The reversal of 261553251266677 is 776662152355162.

It is a cyclic number.

It is not a de Polignac number, because 261553251266677 - 2³¹ = 261551103783029 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 (261553251266687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24482277 + ... + 33503557.

It is an arithmetic number, because the mean of its divisors is an integer number (17257802678820).

Almost surely, 2^{261553251266677} is an apocalyptic number.

It is an amenable number.

261553251266677 is a deficient number, since it is larger than the sum of its proper divisors (14571591594443).

261553251266677 is a wasteful number, since it uses less digits than its factorization.

261553251266677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9025764.

The product of its digits is 190512000, while the sum is 64.

The spelling of 261553251266677 in words is "two hundred sixty-one trillion, five hundred fifty-three billion, two hundred fifty-one million, two hundred sixty-six thousand, six hundred seventy-seven".