20101978894 has 32 divisors (see below), whose sum is σ = 31663288800. Its totient is φ = 9558998400.

The previous prime is 20101978889. The next prime is 20101978907. The reversal of 20101978894 is 49887910102.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1145317 + ... + 1162735.

It is an arithmetic number, because the mean of its divisors is an integer number (989477775).

Almost surely, 2^20101978894 is an apocalyptic number.

20101978894 is a deficient number, since it is larger than the sum of its proper divisors (11561309906).

20101978894 is a wasteful number, since it uses less digits than its factorization.

20101978894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17748.

The product of its (nonzero) digits is 290304, while the sum is 49.

The spelling of 20101978894 in words is "twenty billion, one hundred one million, nine hundred seventy-eight thousand, eight hundred ninety-four".