195661840 has 240 divisors, whose sum is σ = 561057840. Its totient is φ = 63078400.

The previous prime is 195661819. The next prime is 195661859. The reversal of 195661840 is 48166591.

It can be written as a sum of positive squares in 8 ways, for example, as 7203856 + 188457984 = 2684^2 + 13728^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 195661793 and 195661802.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4772220 + ... + 4772260.

It is an arithmetic number, because the mean of its divisors is an integer number (2337741).

Almost surely, 2^195661840 is an apocalyptic number.

195661840 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 195661840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280528920).

195661840 is an abundant number, since it is smaller than the sum of its proper divisors (365396000).

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

195661840 is a wasteful number, since it uses less digits than its factorization.

195661840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 195661840 is about 13987.9176434522. The cubic root of 195661840 is about 580.5443165979.

The spelling of 195661840 in words is "one hundred ninety-five million, six hundred sixty-one thousand, eight hundred forty".