5181661 has 4 divisors (see below), whose sum is σ = 5454400. Its totient is φ = 4908924.

The previous prime is 5181653. The next prime is 5181667. The reversal of 5181661 is 1661815.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 5181661 - 2³ = 5181653 is a prime.

It is a super-2 number, since 2×5181661² = 53699221437842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5181667) 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, 136341 + ... + 136378.

It is an arithmetic number, because the mean of its divisors is an integer number (1363600).

Almost surely, 2^5181661 is an apocalyptic number.

It is an amenable number.

5181661 is a deficient number, since it is larger than the sum of its proper divisors (272739).

5181661 is a wasteful number, since it uses less digits than its factorization.

5181661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272738.

The product of its digits is 1440, while the sum is 28.

The square root of 5181661 is about 2276.3262068517. The cubic root of 5181661 is about 173.0439150323.

The spelling of 5181661 in words is "five million, one hundred eighty-one thousand, six hundred sixty-one".