261657026023245 has 16 divisors (see below), whose sum is σ = 418671733108992. Its totient is φ = 139543583388480.

The previous prime is 261657026023153. The next prime is 261657026023307. The reversal of 261657026023245 is 542320620756162.

It is not a de Polignac number, because 261657026023245 - 2⁷ = 261657026023117 is a prime.

It is a super-2 number, since 2×261657026023245² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 426588982 + ... + 427201911.

It is an arithmetic number, because the mean of its divisors is an integer number (26166983319312).

Almost surely, 2^{261657026023245} is an apocalyptic number.

It is an amenable number.

261657026023245 is a deficient number, since it is larger than the sum of its proper divisors (157014707085747).

261657026023245 is a wasteful number, since it uses less digits than its factorization.

261657026023245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853811332.

The product of its (nonzero) digits is 7257600, while the sum is 51.

The spelling of 261657026023245 in words is "two hundred sixty-one trillion, six hundred fifty-seven billion, twenty-six million, twenty-three thousand, two hundred forty-five".