5531161644 has 18 divisors (see below), whose sum is σ = 13981547580. Its totient is φ = 1843720536.

The previous prime is 5531161637. The next prime is 5531161651. The reversal of 5531161644 is 4461611355.

5531161644 is a `hidden beast` number, since 5 + 5 + 3 + 1 + 1 + 6 + 1 + 644 = 666.

It is an interprime number because it is at equal distance from previous prime (5531161637) and next prime (5531161651).

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 153643379 = 5531161644 / (5 + 5 + 3 + 1 + 1 + 6 + 1 + 6 + 4 + 4).

It is a junction number, because it is equal to n+sod(n) for n = 5531161599 and 5531161608.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 76821654 + ... + 76821725.

Almost surely, 2^5531161644 is an apocalyptic number.

It is an amenable number.

5531161644 is an abundant number, since it is smaller than the sum of its proper divisors (8450385936).

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

5531161644 is a wasteful number, since it uses less digits than its factorization.

5531161644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153643389 (or 153643384 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 5531161644 is about 74371.7798899556. The cubic root of 5531161644 is about 1768.5015720146.

Adding to 5531161644 its reverse (4461611355), we get a palindrome (9992772999).

The spelling of 5531161644 in words is "five billion, five hundred thirty-one million, one hundred sixty-one thousand, six hundred forty-four".