55331021 has 8 divisors (see below), whose sum is σ = 59818080. Its totient is φ = 51001488.

The previous prime is 55331011. The next prime is 55331041. The reversal of 55331021 is 12013355.

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 55331021 - 2¹⁰ = 55329997 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 55330984 and 55331002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55331011) 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, 38651 + ... + 40056.

It is an arithmetic number, because the mean of its divisors is an integer number (7477260).

Almost surely, 2^55331021 is an apocalyptic number.

It is an amenable number.

55331021 is a deficient number, since it is larger than the sum of its proper divisors (4487059).

55331021 is a wasteful number, since it uses less digits than its factorization.

55331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78763.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 55331021 is about 7438.4824393152. The cubic root of 55331021 is about 381.0566642781.

Adding to 55331021 its reverse (12013355), we get a palindrome (67344376).

The spelling of 55331021 in words is "fifty-five million, three hundred thirty-one thousand, twenty-one".