20929506978 has 8 divisors (see below), whose sum is σ = 41859013968. Its totient is φ = 6976502324.

The previous prime is 20929506947. The next prime is 20929506989. The reversal of 20929506978 is 87960592902.

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

20929506978 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1744125576 + ... + 1744125587.

It is an arithmetic number, because the mean of its divisors is an integer number (5232376746).

Almost surely, 2^20929506978 is an apocalyptic number.

20929506978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20929506978 is a wasteful number, since it uses less digits than its factorization.

20929506978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3488251168.

The product of its (nonzero) digits is 4898880, while the sum is 57.

The spelling of 20929506978 in words is "twenty billion, nine hundred twenty-nine million, five hundred six thousand, nine hundred seventy-eight".