199394022978 has 64 divisors (see below), whose sum is σ = 466487923200. Its totient is φ = 62957198160.

The previous prime is 199394022953. The next prime is 199394022983. The reversal of 199394022978 is 879220493991.

199394022978 is a `hidden beast` number, since 19 + 9 + 394 + 0 + 229 + 7 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11042025 + ... + 11060067.

It is an arithmetic number, because the mean of its divisors is an integer number (7288873800).

Almost surely, 2^199394022978 is an apocalyptic number.

199394022978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

199394022978 is an abundant number, since it is smaller than the sum of its proper divisors (267093900222).

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

199394022978 is a wasteful number, since it uses less digits than its factorization.

199394022978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28844 (or 28838 counting only the distinct ones).

The product of its (nonzero) digits is 17635968, while the sum is 63.

The spelling of 199394022978 in words is "one hundred ninety-nine billion, three hundred ninety-four million, twenty-two thousand, nine hundred seventy-eight".