20392978 has 8 divisors (see below), whose sum is σ = 31576320. Its totient is φ = 9867540.

The previous prime is 20392963. The next prime is 20392987. The reversal of 20392978 is 87929302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20392978.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164398 + ... + 164521.

It is an arithmetic number, because the mean of its divisors is an integer number (3947040).

Almost surely, 2^20392978 is an apocalyptic number.

20392978 is a deficient number, since it is larger than the sum of its proper divisors (11183342).

20392978 is a wasteful number, since it uses less digits than its factorization.

20392978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328952.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 20392978 is about 4515.8585008833. The cubic root of 20392978 is about 273.2080869109.

The spelling of 20392978 in words is "twenty million, three hundred ninety-two thousand, nine hundred seventy-eight".