55443021 has 4 divisors (see below), whose sum is σ = 73924032. Its totient is φ = 36962012.

The previous prime is 55443019. The next prime is 55443023. The reversal of 55443021 is 12034455.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (55443019) and next prime (55443023).

It is a cyclic number.

It is not a de Polignac number, because 55443021 - 2¹ = 55443019 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 55442982 and 55443000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55443023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9240501 + ... + 9240506.

It is an arithmetic number, because the mean of its divisors is an integer number (18481008).

Almost surely, 2^55443021 is an apocalyptic number.

It is an amenable number.

55443021 is a deficient number, since it is larger than the sum of its proper divisors (18481011).

55443021 is a wasteful number, since it uses less digits than its factorization.

55443021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18481010.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 55443021 is about 7446.0070507622. The cubic root of 55443021 is about 381.3136002111.

Adding to 55443021 its reverse (12034455), we get a palindrome (67477476).

The spelling of 55443021 in words is "fifty-five million, four hundred forty-three thousand, twenty-one".