166520655 has 48 divisors (see below), whose sum is σ = 347243520. Its totient is φ = 72114624.

The previous prime is 166520603. The next prime is 166520663. The reversal of 166520655 is 556025661.

It is a happy number.

It is not a de Polignac number, because 166520655 - 2⁶ = 166520591 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7927 + ... + 19896.

It is an arithmetic number, because the mean of its divisors is an integer number (7234240).

Almost surely, 2^166520655 is an apocalyptic number.

166520655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

166520655 is an abundant number, since it is smaller than the sum of its proper divisors (180722865).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166520655 is a wasteful number, since it uses less digits than its factorization.

166520655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27860 (or 27857 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 166520655 is about 12904.2882407361. The cubic root of 166520655 is about 550.1604545626.

The spelling of 166520655 in words is "one hundred sixty-six million, five hundred twenty thousand, six hundred fifty-five".