55151821 has 8 divisors (see below), whose sum is σ = 58143744. Its totient is φ = 52235760.

The previous prime is 55151819. The next prime is 55151827. The reversal of 55151821 is 12815155.

55151821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 55151821 - 2¹ = 55151819 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 55151821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55151827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17470 + ... + 20383.

It is an arithmetic number, because the mean of its divisors is an integer number (7267968).

Almost surely, 2^55151821 is an apocalyptic number.

It is an amenable number.

55151821 is a deficient number, since it is larger than the sum of its proper divisors (2991923).

55151821 is a wasteful number, since it uses less digits than its factorization.

55151821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37931.

The product of its digits is 2000, while the sum is 28.

The square root of 55151821 is about 7426.4272029018. The cubic root of 55151821 is about 380.6448446256.

Adding to 55151821 its reverse (12815155), we get a palindrome (67966976).

The spelling of 55151821 in words is "fifty-five million, one hundred fifty-one thousand, eight hundred twenty-one".