55615181 has 4 divisors (see below), whose sum is σ = 57118332. Its totient is φ = 54112032.

The previous prime is 55615171. The next prime is 55615207. The reversal of 55615181 is 18151655.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18151655 = 5 ⋅3630331.

It can be written as a sum of positive squares in 2 ways, for example, as 43428100 + 12187081 = 6590^2 + 3491^2 .

It is a cyclic number.

It is not a de Polignac number, because 55615181 - 2⁶ = 55615117 is a prime.

It is a super-2 number, since 2×55615181² = 6186096715325522, 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 (55615141) 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, 751520 + ... + 751593.

It is an arithmetic number, because the mean of its divisors is an integer number (14279583).

Almost surely, 2^55615181 is an apocalyptic number.

It is an amenable number.

55615181 is a deficient number, since it is larger than the sum of its proper divisors (1503151).

55615181 is a wasteful number, since it uses less digits than its factorization.

55615181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1503150.

The product of its digits is 6000, while the sum is 32.

The square root of 55615181 is about 7457.5586487804. The cubic root of 55615181 is about 381.7078735683.

The spelling of 55615181 in words is "fifty-five million, six hundred fifteen thousand, one hundred eighty-one".