199923178068 has 72 divisors (see below), whose sum is σ = 524213114880. Its totient is φ = 64167647040.

The previous prime is 199923178061. The next prime is 199923178079. The reversal of 199923178068 is 860871329991.

It is a junction number, because it is equal to n+sod(n) for n = 199923177996 and 199923178014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199923178061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 122253 + ... + 644043.

Almost surely, 2^199923178068 is an apocalyptic number.

199923178068 is a gapful number since it is divisible by the number (18) 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 199923178068, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262106557440).

199923178068 is an abundant number, since it is smaller than the sum of its proper divisors (324289936812).

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

199923178068 is a wasteful number, since it uses less digits than its factorization.

199923178068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522197 (or 522192 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 63.

The spelling of 199923178068 in words is "one hundred ninety-nine billion, nine hundred twenty-three million, one hundred seventy-eight thousand, sixty-eight".