55012021 has 4 divisors (see below), whose sum is σ = 57403872. Its totient is φ = 52620172.

The previous prime is 55012003. The next prime is 55012031. The reversal of 55012021 is 12021055.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12021055 = 5 ⋅2404211.

It is a cyclic number.

It is not a de Polignac number, because 55012021 - 2⁵ = 55011989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55011986 and 55012004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55012031) 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, 1195891 + ... + 1195936.

It is an arithmetic number, because the mean of its divisors is an integer number (14350968).

Almost surely, 2^55012021 is an apocalyptic number.

It is an amenable number.

55012021 is a deficient number, since it is larger than the sum of its proper divisors (2391851).

55012021 is a wasteful number, since it uses less digits than its factorization.

55012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2391850.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 55012021 is about 7417.0088984711. The cubic root of 55012021 is about 380.3229502952.

Adding to 55012021 its reverse (12021055), we get a palindrome (67033076).

The spelling of 55012021 in words is "fifty-five million, twelve thousand, twenty-one".