55506021 has 8 divisors (see below), whose sum is σ = 74199840. Its totient is φ = 36908112.

The previous prime is 55505993. The next prime is 55506023. The reversal of 55506021 is 12060555.

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

It is not a de Polignac number, because 55506021 - 2¹⁰ = 55504997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55505982 and 55506000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55506023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22615 + ... + 24948.

It is an arithmetic number, because the mean of its divisors is an integer number (9274980).

Almost surely, 2^55506021 is an apocalyptic number.

It is an amenable number.

55506021 is a deficient number, since it is larger than the sum of its proper divisors (18693819).

55506021 is a wasteful number, since it uses less digits than its factorization.

55506021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47955.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 55506021 is about 7450.2363049772. The cubic root of 55506021 is about 381.4579746402.

Adding to 55506021 its reverse (12060555), we get a palindrome (67566576).

The spelling of 55506021 in words is "fifty-five million, five hundred six thousand, twenty-one".