194020978 has 4 divisors (see below), whose sum is σ = 291031470. Its totient is φ = 97010488.

The previous prime is 194020973. The next prime is 194020987. The reversal of 194020978 is 879020491.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 131721529 + 62299449 = 11477^2 + 7893^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 194020978.

It is not an unprimeable number, because it can be changed into a prime (194020973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48505243 + ... + 48505246.

Almost surely, 2^194020978 is an apocalyptic number.

194020978 is a deficient number, since it is larger than the sum of its proper divisors (97010492).

194020978 is an equidigital number, since it uses as much as digits as its factorization.

194020978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97010491.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 194020978 is about 13929.1413231398. The cubic root of 194020978 is about 578.9169025728.

The spelling of 194020978 in words is "one hundred ninety-four million, twenty thousand, nine hundred seventy-eight".