161366774400 has 1344 divisors, whose sum is σ = 683678976120. Its totient is φ = 37265080320.

The previous prime is 161366774357. The next prime is 161366774411. The reversal of 161366774400 is 4477663161.

161366774400 is a `hidden beast` number, since 1 + 6 + 136 + 6 + 77 + 440 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 3579868224 + 157786906176 = 59832^2 + 397224^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 515548644 + ... + 515548956.

Almost surely, 2^161366774400 is an apocalyptic number.

161366774400 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 161366774400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (341839488060).

161366774400 is an abundant number, since it is smaller than the sum of its proper divisors (522312201720).

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

161366774400 is a wasteful number, since it uses less digits than its factorization.

161366774400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 161366774400 in words is "one hundred sixty-one billion, three hundred sixty-six million, seven hundred seventy-four thousand, four hundred".