195997780 has 48 divisors (see below), whose sum is σ = 455749056. Its totient is φ = 70202880.

The previous prime is 195997771. The next prime is 195997793. The reversal of 195997780 is 87799591.

195997780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8092 + ... + 21388.

It is an arithmetic number, because the mean of its divisors is an integer number (9494772).

Almost surely, 2^195997780 is an apocalyptic number.

195997780 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 195997780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227874528).

195997780 is an abundant number, since it is smaller than the sum of its proper divisors (259751276).

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

195997780 is a wasteful number, since it uses less digits than its factorization.

195997780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13384 (or 13382 counting only the distinct ones).

The product of its (nonzero) digits is 1428840, while the sum is 55.

The square root of 195997780 is about 13999.9207140612. The cubic root of 195997780 is about 580.8763802351.

The spelling of 195997780 in words is "one hundred ninety-five million, nine hundred ninety-seven thousand, seven hundred eighty".