161668799040 has 896 divisors, whose sum is σ = 641513779200. Its totient is φ = 33673052160.

The previous prime is 161668798909. The next prime is 161668799063. The reversal of 161668799040 is 40997866161.

It is a super-2 number, since 2×161668799040² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 465904147 + ... + 465904493.

It is an arithmetic number, because the mean of its divisors is an integer number (715975200).

Almost surely, 2^161668799040 is an apocalyptic number.

161668799040 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 161668799040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (320756889600).

161668799040 is an abundant number, since it is smaller than the sum of its proper divisors (479844980160).

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

161668799040 is a wasteful number, since it uses less digits than its factorization.

161668799040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 57.

The spelling of 161668799040 in words is "one hundred sixty-one billion, six hundred sixty-eight million, seven hundred ninety-nine thousand, forty".