197778 has 32 divisors (see below), whose sum is σ = 480384. Its totient is φ = 52992.

The previous prime is 197773. The next prime is 197779. The reversal of 197778 is 877791.

It is a happy number.

It is a super-2 number, since 2×197778² = 78232274568, which contains 22 as substring.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (197773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 576 + ... + 852.

It is an arithmetic number, because the mean of its divisors is an integer number (15012).

2¹⁹⁷⁷⁷⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 197778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240192).

197778 is an abundant number, since it is smaller than the sum of its proper divisors (282606).

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

197778 is a wasteful number, since it uses less digits than its factorization.

197778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306.

The product of its digits is 24696, while the sum is 39.

The square root of 197778 is about 444.7223853147. The cubic root of 197778 is about 58.2629754906.

It can be divided in two parts, 1 and 97778, that added together give a palindrome (97779).

The spelling of 197778 in words is "one hundred ninety-seven thousand, seven hundred seventy-eight".