16561500746551 has 16 divisors (see below), whose sum is σ = 17671423714560. Its totient is φ = 15476838661440.

The previous prime is 16561500746519. The next prime is 16561500746561. The reversal of 16561500746551 is 15564700516561.

16561500746551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 16561500746551 - 2⁵ = 16561500746519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561500746561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19506126 + ... + 20337451.

It is an arithmetic number, because the mean of its divisors is an integer number (1104463982160).

Almost surely, 2^{16561500746551} is an apocalyptic number.

16561500746551 is a deficient number, since it is larger than the sum of its proper divisors (1109922968009).

16561500746551 is a wasteful number, since it uses less digits than its factorization.

16561500746551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39843894.

The product of its (nonzero) digits is 3780000, while the sum is 52.

The spelling of 16561500746551 in words is "sixteen trillion, five hundred sixty-one billion, five hundred million, seven hundred forty-six thousand, five hundred fifty-one".