16121561564 has 12 divisors (see below), whose sum is σ = 29185585800. Its totient is φ = 7782822768.

The previous prime is 16121561531. The next prime is 16121561627. The reversal of 16121561564 is 46516512161.

16121561564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 69489374 + ... + 69489605.

It is an arithmetic number, because the mean of its divisors is an integer number (2432132150).

Almost surely, 2^16121561564 is an apocalyptic number.

It is an amenable number.

16121561564 is a deficient number, since it is larger than the sum of its proper divisors (13064024236).

16121561564 is a wasteful number, since it uses less digits than its factorization.

16121561564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138979012 (or 138979010 counting only the distinct ones).

The product of its digits is 43200, while the sum is 38.

The spelling of 16121561564 in words is "sixteen billion, one hundred twenty-one million, five hundred sixty-one thousand, five hundred sixty-four".