199215378 has 12 divisors (see below), whose sum is σ = 431633358. Its totient is φ = 66405120.

The previous prime is 199215371. The next prime is 199215449. The reversal of 199215378 is 873512991.

199215378 is a `hidden beast` number, since 1 + 99 + 21 + 537 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 129208689 + 70006689 = 11367^2 + 8367^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (199215371) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5533743 + ... + 5533778.

Almost surely, 2^199215378 is an apocalyptic number.

199215378 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

199215378 is an abundant number, since it is smaller than the sum of its proper divisors (232417980).

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

199215378 is a wasteful number, since it uses less digits than its factorization.

199215378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11067529 (or 11067526 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 199215378 is about 14114.3677860540. The cubic root of 199215378 is about 584.0377958431.

The spelling of 199215378 in words is "one hundred ninety-nine million, two hundred fifteen thousand, three hundred seventy-eight".