5661551551 has 4 divisors (see below), whose sum is σ = 5662630512. Its totient is φ = 5660472592.

The previous prime is 5661551549. The next prime is 5661551611. The reversal of 5661551551 is 1551551665.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 5661551551 - 2¹ = 5661551549 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 (5661551851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531571 + ... + 542116.

It is an arithmetic number, because the mean of its divisors is an integer number (1415657628).

Almost surely, 2^5661551551 is an apocalyptic number.

5661551551 is a deficient number, since it is larger than the sum of its proper divisors (1078961).

5661551551 is a wasteful number, since it uses less digits than its factorization.

5661551551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078960.

The product of its digits is 112500, while the sum is 40.

The square root of 5661551551 is about 75243.2824310583. The cubic root of 5661551551 is about 1782.2904855881.

The spelling of 5661551551 in words is "five billion, six hundred sixty-one million, five hundred fifty-one thousand, five hundred fifty-one".