5161661556 has 12 divisors (see below), whose sum is σ = 12043876992. Its totient is φ = 1720553848.

The previous prime is 5161661521. The next prime is 5161661597. The reversal of 5161661556 is 6551661615.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×5161661556² = 53285500037376682272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215069220 + ... + 215069243.

It is an arithmetic number, because the mean of its divisors is an integer number (1003656416).

Almost surely, 2^5161661556 is an apocalyptic number.

It is an amenable number.

5161661556 is an abundant number, since it is smaller than the sum of its proper divisors (6882215436).

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

5161661556 is a wasteful number, since it uses less digits than its factorization.

5161661556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430138470 (or 430138468 counting only the distinct ones).

The product of its digits is 162000, while the sum is 42.

The square root of 5161661556 is about 71844.7044395062. The cubic root of 5161661556 is about 1728.2099782879.

The spelling of 5161661556 in words is "five billion, one hundred sixty-one million, six hundred sixty-one thousand, five hundred fifty-six".