16991521386 has 32 divisors (see below), whose sum is σ = 41122339200. Its totient is φ = 4569148416.

The previous prime is 16991521373. The next prime is 16991521441. The reversal of 16991521386 is 68312519961.

16991521386 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 11898111 + ... + 11899538.

It is an arithmetic number, because the mean of its divisors is an integer number (1285073100).

Almost surely, 2^16991521386 is an apocalyptic number.

16991521386 is an abundant number, since it is smaller than the sum of its proper divisors (24130817814).

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

16991521386 is a wasteful number, since it uses less digits than its factorization.

16991521386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23797678.

The product of its digits is 699840, while the sum is 51.

The spelling of 16991521386 in words is "sixteen billion, nine hundred ninety-one million, five hundred twenty-one thousand, three hundred eighty-six".