166138905600 has 792 divisors, whose sum is σ = 653590855008. Its totient is φ = 41671065600.

The previous prime is 166138905553. The next prime is 166138905607. The reversal of 166138905600 is 6509831661.

166138905600 is a `hidden beast` number, since 1 + 6 + 6 + 1 + 3 + 89 + 0 + 560 + 0 = 666.

It is a super-2 number, since 2×166138905600² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166138905607) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 105752815 + ... + 105754385.

Almost surely, 2^166138905600 is an apocalyptic number.

166138905600 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 166138905600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326795427504).

166138905600 is an abundant number, since it is smaller than the sum of its proper divisors (487451949408).

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

166138905600 is a wasteful number, since it uses less digits than its factorization.

166138905600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1633 (or 1598 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 166138905600 in words is "one hundred sixty-six billion, one hundred thirty-eight million, nine hundred five thousand, six hundred".