166399304544 has 432 divisors, whose sum is σ = 531999468000. Its totient is φ = 49286983680.

The previous prime is 166399304483. The next prime is 166399304551. The reversal of 166399304544 is 445403993661.

It is a happy number.

166399304544 is a `hidden beast` number, since 1 + 6 + 6 + 3 + 9 + 93 + 0 + 4 + 544 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 379041477 + ... + 379041915.

It is an arithmetic number, because the mean of its divisors is an integer number (1231480250).

Almost surely, 2^166399304544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166399304544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265999734000).

166399304544 is an abundant number, since it is smaller than the sum of its proper divisors (365600163456).

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

166399304544 is a wasteful number, since it uses less digits than its factorization.

166399304544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699 (or 677 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 54.

The spelling of 166399304544 in words is "one hundred sixty-six billion, three hundred ninety-nine million, three hundred four thousand, five hundred forty-four".