3544111221561 has 27 divisors (see below), whose sum is σ = 5149196497263. Its totient is φ = 2349009268560.

The previous prime is 3544111221487. The next prime is 3544111221569. The reversal of 3544111221561 is 1651221114453.

The square root of 3544111221561 is 1882581.

It is a perfect power (a square), and thus also a powerful number.

3544111221561 is a `hidden beast` number, since 3 + 54 + 4 + 11 + 12 + 21 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 39053269161 + 3505057952400 = 197619^2 + 1872180^2 .

It is not a de Polignac number, because 3544111221561 - 2¹⁹ = 3544110697273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3544111221569) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1022239750 + ... + 1022243216.

Almost surely, 2^{3544111221561} is an apocalyptic number.

3544111221561 is the 1882581-st square number.

3544111221561 is the 941291-st centered octagonal number.

It is an amenable number.

3544111221561 is a deficient number, since it is larger than the sum of its proper divisors (1605085275702).

3544111221561 is an frugal number, since it uses more digits than its factorization.

3544111221561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7302 (or 3651 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

Multiplying 3544111221561 by its sum of digits (36), we get a square (127588003976196 = 11295486²).

The spelling of 3544111221561 in words is "three trillion, five hundred forty-four billion, one hundred eleven million, two hundred twenty-one thousand, five hundred sixty-one".