16421699978 has 8 divisors (see below), whose sum is σ = 24676303968. Its totient is φ = 8196265324.

The previous prime is 16421699977. The next prime is 16421700037. The reversal of 16421699978 is 87999612461.

16421699978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 16421699978.

It is not an unprimeable number, because it can be changed into a prime (16421699971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7290926 + ... + 7293177.

It is an arithmetic number, because the mean of its divisors is an integer number (3084537996).

Almost surely, 2^16421699978 is an apocalyptic number.

16421699978 is a deficient number, since it is larger than the sum of its proper divisors (8254603990).

16421699978 is a wasteful number, since it uses less digits than its factorization.

16421699978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14584668.

The product of its digits is 11757312, while the sum is 62.

The spelling of 16421699978 in words is "sixteen billion, four hundred twenty-one million, six hundred ninety-nine thousand, nine hundred seventy-eight".