55042021 has 8 divisors (see below), whose sum is σ = 56463264. Its totient is φ = 53627280.

The previous prime is 55041991. The next prime is 55042027. The reversal of 55042021 is 12024055.

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 55042021 - 2¹³ = 55033829 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55042021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55042027) 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, 18711 + ... + 21451.

It is an arithmetic number, because the mean of its divisors is an integer number (7057908).

Almost surely, 2^55042021 is an apocalyptic number.

It is an amenable number.

55042021 is a deficient number, since it is larger than the sum of its proper divisors (1421243).

55042021 is a wasteful number, since it uses less digits than its factorization.

55042021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3251.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 55042021 is about 7419.0310014179. The cubic root of 55042021 is about 380.3920722488.

Adding to 55042021 its reverse (12024055), we get a palindrome (67066076).

The spelling of 55042021 in words is "fifty-five million, forty-two thousand, twenty-one".