195639840 has 384 divisors, whose sum is σ = 783820800. Its totient is φ = 45112320.

The previous prime is 195639797. The next prime is 195639841. The reversal of 195639840 is 48936591.

It is a happy number.

195639840 is a `hidden beast` number, since 1 + 9 + 5 + 639 + 8 + 4 + 0 = 666.

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 (195639841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1092871 + ... + 1093049.

It is an arithmetic number, because the mean of its divisors is an integer number (2041200).

Almost surely, 2^195639840 is an apocalyptic number.

195639840 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 195639840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391910400).

195639840 is an abundant number, since it is smaller than the sum of its proper divisors (588180960).

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

195639840 is a wasteful number, since it uses less digits than its factorization.

195639840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 223 counting only the distinct ones).

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

The square root of 195639840 is about 13987.1312283828. The cubic root of 195639840 is about 580.5225571962.

It can be divided in two parts, 19563 and 9840, that added together give a triangular number (29403 = T₂₄₂).

The spelling of 195639840 in words is "one hundred ninety-five million, six hundred thirty-nine thousand, eight hundred forty".