166581655455 has 16 divisors (see below), whose sum is σ = 270508719744. Its totient is φ = 87517525920.

The previous prime is 166581655447. The next prime is 166581655463. The reversal of 166581655455 is 554556185661.

It is an interprime number because it is at equal distance from previous prime (166581655447) and next prime (166581655463).

It is not a de Polignac number, because 166581655455 - 2³ = 166581655447 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 166581655395 and 166581655404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82875441 + ... + 82877450.

It is an arithmetic number, because the mean of its divisors is an integer number (16906794984).

Almost surely, 2^166581655455 is an apocalyptic number.

166581655455 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

166581655455 is a deficient number, since it is larger than the sum of its proper divisors (103927064289).

166581655455 is a wasteful number, since it uses less digits than its factorization.

166581655455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165752966.

The product of its digits is 21600000, while the sum is 57.

It can be divided in two parts, 1665816 and 55455, that added together give a palindrome (1721271).

The spelling of 166581655455 in words is "one hundred sixty-six billion, five hundred eighty-one million, six hundred fifty-five thousand, four hundred fifty-five".