166581294390 has 384 divisors, whose sum is σ = 545147366400. Its totient is φ = 35728293888.

The previous prime is 166581294377. The next prime is 166581294403. The reversal of 166581294390 is 93492185661.

166581294390 is a `hidden beast` number, since 1 + 6 + 6 + 581 + 29 + 4 + 39 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (166581294377) and next prime (166581294403).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 129836689 + ... + 129837971.

It is an arithmetic number, because the mean of its divisors is an integer number (1419654600).

Almost surely, 2^166581294390 is an apocalyptic number.

166581294390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 166581294390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272573683200).

166581294390 is an abundant number, since it is smaller than the sum of its proper divisors (378566072010).

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

166581294390 is a wasteful number, since it uses less digits than its factorization.

166581294390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1778 (or 1766 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The spelling of 166581294390 in words is "one hundred sixty-six billion, five hundred eighty-one million, two hundred ninety-four thousand, three hundred ninety".