55005621 has 16 divisors (see below), whose sum is σ = 80248320. Its totient is φ = 33236720.

The previous prime is 55005583. The next prime is 55005623. The reversal of 55005621 is 12650055.

It is not a de Polignac number, because 55005621 - 2⁹ = 55005109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55005591 and 55005600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55005623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9526 + ... + 14168.

It is an arithmetic number, because the mean of its divisors is an integer number (5015520).

Almost surely, 2^55005621 is an apocalyptic number.

It is an amenable number.

55005621 is a deficient number, since it is larger than the sum of its proper divisors (25242699).

55005621 is a wasteful number, since it uses less digits than its factorization.

55005621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5016.

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

The square root of 55005621 is about 7416.5774451562. The cubic root of 55005621 is about 380.3082010262.

Adding to 55005621 its reverse (12650055), we get a palindrome (67655676).

The spelling of 55005621 in words is "fifty-five million, five thousand, six hundred twenty-one".