16561247472 has 160 divisors (see below), whose sum is σ = 59266920960. Its totient is φ = 4301614080.

The previous prime is 16561247401. The next prime is 16561247473. The reversal of 16561247472 is 27474216561.

16561247472 is a `hidden beast` number, since 1 + 6 + 56 + 124 + 7 + 472 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561247473) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 215673 + ... + 282200.

It is an arithmetic number, because the mean of its divisors is an integer number (370418256).

Almost surely, 2^16561247472 is an apocalyptic number.

16561247472 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

16561247472 is an abundant number, since it is smaller than the sum of its proper divisors (42705673488).

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

16561247472 is a wasteful number, since it uses less digits than its factorization.

16561247472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497908 (or 497896 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The spelling of 16561247472 in words is "sixteen billion, five hundred sixty-one million, two hundred forty-seven thousand, four hundred seventy-two".