166405620640 has 384 divisors, whose sum is σ = 511469199360. Its totient is φ = 49783652352.

The previous prime is 166405620637. The next prime is 166405620677. The reversal of 166405620640 is 46026504661.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 166405620593 and 166405620602.

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 63 ways as a sum of consecutive naturals, for example, 16997827 + ... + 17007613.

It is an arithmetic number, because the mean of its divisors is an integer number (1331951040).

Almost surely, 2^166405620640 is an apocalyptic number.

166405620640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166405620640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255734599680).

166405620640 is an abundant number, since it is smaller than the sum of its proper divisors (345063578720).

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

166405620640 is a wasteful number, since it uses less digits than its factorization.

166405620640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9892 (or 9884 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 166405620640 in words is "one hundred sixty-six billion, four hundred five million, six hundred twenty thousand, six hundred forty".