55612321 has 8 divisors (see below), whose sum is σ = 61444224. Its totient is φ = 50064960.

The previous prime is 55612309. The next prime is 55612363. The reversal of 55612321 is 12321655.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55612321 - 2¹⁵ = 55579553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55612391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70725 + ... + 71506.

It is an arithmetic number, because the mean of its divisors is an integer number (7680528).

Almost surely, 2^55612321 is an apocalyptic number.

It is an amenable number.

55612321 is a deficient number, since it is larger than the sum of its proper divisors (5831903).

55612321 is a wasteful number, since it uses less digits than its factorization.

55612321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142271.

The product of its digits is 1800, while the sum is 25.

The square root of 55612321 is about 7457.3668945547. The cubic root of 55612321 is about 381.7013303715.

Adding to 55612321 its reverse (12321655), we get a palindrome (67933976).

The spelling of 55612321 in words is "fifty-five million, six hundred twelve thousand, three hundred twenty-one".