55271021 has 4 divisors (see below), whose sum is σ = 59522652. Its totient is φ = 51019392.

The previous prime is 55270991. The next prime is 55271077. The reversal of 55271021 is 12017255.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12017255 = 5 ⋅2403451.

It can be written as a sum of positive squares in 2 ways, for example, as 11526025 + 43744996 = 3395^2 + 6614^2 .

It is a cyclic number.

It is not a de Polignac number, because 55271021 - 2¹⁰ = 55269997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55271521) 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, 2125796 + ... + 2125821.

It is an arithmetic number, because the mean of its divisors is an integer number (14880663).

Almost surely, 2^55271021 is an apocalyptic number.

It is an amenable number.

55271021 is a deficient number, since it is larger than the sum of its proper divisors (4251631).

55271021 is a wasteful number, since it uses less digits than its factorization.

55271021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4251630.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 55271021 is about 7434.4482646663. The cubic root of 55271021 is about 380.9188773812.

Adding to 55271021 its reverse (12017255), we get a palindrome (67288276).

The spelling of 55271021 in words is "fifty-five million, two hundred seventy-one thousand, twenty-one".