20782978 has 8 divisors (see below), whose sum is σ = 31613760. Its totient is φ = 10245060.

The previous prime is 20782969. The next prime is 20782981. The reversal of 20782978 is 87928702.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73038 + ... + 73321.

It is an arithmetic number, because the mean of its divisors is an integer number (3951720).

Almost surely, 2^20782978 is an apocalyptic number.

20782978 is a deficient number, since it is larger than the sum of its proper divisors (10830782).

20782978 is a wasteful number, since it uses less digits than its factorization.

20782978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146432.

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 20782978 is about 4558.8351582394. The cubic root of 20782978 is about 274.9387323566.

The spelling of 20782978 in words is "twenty million, seven hundred eighty-two thousand, nine hundred seventy-eight".