166599145440 has 864 divisors, whose sum is σ = 734644481760. Its totient is φ = 35143041024.

The previous prime is 166599145423. The next prime is 166599145441. The reversal of 166599145440 is 44541995661.

166599145440 is a `hidden beast` number, since 1 + 6 + 6 + 5 + 9 + 91 + 4 + 544 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×166599145440² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166599145441) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 35771592 + ... + 35776248.

It is an arithmetic number, because the mean of its divisors is an integer number (850282965).

Almost surely, 2^166599145440 is an apocalyptic number.

166599145440 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 166599145440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (367322240880).

166599145440 is an abundant number, since it is smaller than the sum of its proper divisors (568045336320).

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

166599145440 is a wasteful number, since it uses less digits than its factorization.

166599145440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4721 (or 4687 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 54.

The spelling of 166599145440 in words is "one hundred sixty-six billion, five hundred ninety-nine million, one hundred forty-five thousand, four hundred forty".