2581666263855 has 96 divisors (see below), whose sum is σ = 5167841078400. Its totient is φ = 1167830286336.

The previous prime is 2581666263853. The next prime is 2581666263881. The reversal of 2581666263855 is 5583626661852.

It is a happy number.

It is not a de Polignac number, because 2581666263855 - 2¹ = 2581666263853 is a prime.

It is a super-2 number, since 2×2581666263855² (a number of 26 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 2581666263792 and 2581666263801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581666263853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 26354727 + ... + 26452503.

It is an arithmetic number, because the mean of its divisors is an integer number (53831677900).

Almost surely, 2^{2581666263855} is an apocalyptic number.

2581666263855 is an abundant number, since it is smaller than the sum of its proper divisors (2586174814545).

2581666263855 is a wasteful number, since it uses less digits than its factorization.

2581666263855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98673 (or 98670 counting only the distinct ones).

The product of its digits is 124416000, while the sum is 63.

The spelling of 2581666263855 in words is "two trillion, five hundred eighty-one billion, six hundred sixty-six million, two hundred sixty-three thousand, eight hundred fifty-five".