55021212 has 36 divisors (see below), whose sum is σ = 139819680. Its totient is φ = 18243072.

The previous prime is 55021189. The next prime is 55021223. The reversal of 55021212 is 21212055.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2989 + ... + 10907.

It is an arithmetic number, because the mean of its divisors is an integer number (3883880).

Almost surely, 2^55021212 is an apocalyptic number.

It is an amenable number.

55021212 is an abundant number, since it is smaller than the sum of its proper divisors (84798468).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55021212 is a wasteful number, since it uses less digits than its factorization.

55021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8122 (or 8117 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 55021212 is about 7417.6284619816. The cubic root of 55021212 is about 380.3441296272.

Adding to 55021212 its reverse (21212055), we get a palindrome (76233267).

The spelling of 55021212 in words is "fifty-five million, twenty-one thousand, two hundred twelve".