161911958400 has 768 divisors, whose sum is σ = 622322073600. Its totient is φ = 41057280000.

The previous prime is 161911958393. The next prime is 161911958407. The reversal of 161911958400 is 4859119161.

161911958400 is a `hidden beast` number, since 1 + 6 + 191 + 1 + 9 + 58 + 400 = 666.

It is an interprime number because it is at equal distance from previous prime (161911958393) and next prime (161911958407).

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 (161911958407) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 163381905 + ... + 163382895.

It is an arithmetic number, because the mean of its divisors is an integer number (810315200).

Almost surely, 2^161911958400 is an apocalyptic number.

161911958400 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 161911958400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311161036800).

161911958400 is an abundant number, since it is smaller than the sum of its proper divisors (460410115200).

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

161911958400 is a wasteful number, since it uses less digits than its factorization.

161911958400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116 (or 1093 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 45.

The spelling of 161911958400 in words is "one hundred sixty-one billion, nine hundred eleven million, nine hundred fifty-eight thousand, four hundred".