55535021 has 4 divisors (see below), whose sum is σ = 56159100. Its totient is φ = 54910944.

The previous prime is 55535017. The next prime is 55535023. The reversal of 55535021 is 12053555.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12053555 = 5 ⋅2410711.

It can be written as a sum of positive squares in 2 ways, for example, as 3189796 + 52345225 = 1786^2 + 7235^2 .

It is a cyclic number.

It is not a de Polignac number, because 55535021 - 2² = 55535017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55535023) 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, 311906 + ... + 312083.

It is an arithmetic number, because the mean of its divisors is an integer number (14039775).

Almost surely, 2^55535021 is an apocalyptic number.

It is an amenable number.

55535021 is a deficient number, since it is larger than the sum of its proper divisors (624079).

55535021 is an equidigital number, since it uses as much as digits as its factorization.

55535021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624078.

The product of its (nonzero) digits is 3750, while the sum is 26.

The square root of 55535021 is about 7452.1822978239. The cubic root of 55535021 is about 381.5243959946.

Adding to 55535021 its reverse (12053555), we get a palindrome (67588576).

The spelling of 55535021 in words is "fifty-five million, five hundred thirty-five thousand, twenty-one".