27744351561 has 6 divisors (see below), whose sum is σ = 40075174490. Its totient is φ = 18496234368.

The previous prime is 27744351521. The next prime is 27744351587. The reversal of 27744351561 is 16515344772.

27744351561 is a `hidden beast` number, since 2 + 7 + 74 + 4 + 3 + 515 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 26502212025 + 1242139536 = 162795^2 + 35244^2 .

It is not a de Polignac number, because 27744351561 - 2⁷ = 27744351433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27744351521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1541352856 + ... + 1541352873.

Almost surely, 2^27744351561 is an apocalyptic number.

It is an amenable number.

27744351561 is a deficient number, since it is larger than the sum of its proper divisors (12330822929).

27744351561 is a wasteful number, since it uses less digits than its factorization.

27744351561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3082705735 (or 3082705732 counting only the distinct ones).

The product of its digits is 705600, while the sum is 45.

The spelling of 27744351561 in words is "twenty-seven billion, seven hundred forty-four million, three hundred fifty-one thousand, five hundred sixty-one".